From patchwork Tue May 25 12:23:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= X-Patchwork-Id: 12278631 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FFF0C2B9F8 for ; Tue, 25 May 2021 12:24:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12ECD6141B for ; Tue, 25 May 2021 12:24:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232179AbhEYMZt (ORCPT ); Tue, 25 May 2021 08:25:49 -0400 Received: from mail-pf1-f172.google.com ([209.85.210.172]:37718 "EHLO mail-pf1-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232506AbhEYMZr (ORCPT ); Tue, 25 May 2021 08:25:47 -0400 Received: by mail-pf1-f172.google.com with SMTP id q67so6420822pfb.4 for ; Tue, 25 May 2021 05:24:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=6adUKB2Rka82HQabeUv5ibnbMwwIN9gaSFMskphvplI=; b=or+Gr1bdtKf2wsi01wSlPppDmio6iWSO1ZJvNDLzMb81IDZJ76LMixZ/wwO+i3VNUP DsgXBuMasDpNipVRyRH3reVbxEbYrOJC3PF6h0RFFpeqVIwlYX43ygO8vD8xmzb/nYCG 4SYzg7cm4kUMqmBBNCiuqUHs9Wdtp82REvMDD+NIjCe1j5BB6UHQNgtl31xzrW62sm5l pL5ftA69dmoFDLamta+9dP8hEwDJHLye7u1b+HG6+6/HBsIThZreEj0YeM2dlgmKsPdu Mnq5X5/T5b3yKlGoNWSzeBP0CUWty2Z0Nd+2niItR+AwojL5dE2KQ8C6wTiHS3Hpwm1K 6U0g== X-Gm-Message-State: AOAM532tQV0W9cHyNmJCCLPMepIj4+z6/ACArmx9ei1kI4xIn2yYROFm zcnI1/d1oWiJk21qbbF5SSo= X-Google-Smtp-Source: ABdhPJymfMImtdR+SuY7ivBHcrRDPmmJdRcuG2kNZbbZehIPGkNhh32cPrU3vJsB5SH7ITehwxjvaQ== X-Received: by 2002:a65:64cc:: with SMTP id t12mr7590507pgv.64.1621945455703; Tue, 25 May 2021 05:24:15 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id u1sm14220258pfc.63.2021.05.25.05.24.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 05:24:15 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Logan Gunthorpe , Joe Perches , "Oliver O'Halloran" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Tyrel Datwyler , Russell Currey , Kurt Schwemmer , Vidya Sagar , Xiongfeng Wang , linux-pci@vger.kernel.org Subject: [PATCH v4 1/5] PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions Date: Tue, 25 May 2021 12:23:57 +0000 Message-Id: <20210525122401.206136-1-kw@linux.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The sysfs_emit() and sysfs_emit_at() functions were introduced to make it less ambiguous which function is preferred when writing to the output buffer in a device attribute's "show" callback [1]. Convert the PCI sysfs object "show" functions from sprintf(), snprintf() and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the latter is aware of the PAGE_SIZE buffer and correctly returns the number of bytes written into the buffer. No functional change intended. [1] Documentation/filesystems/sysfs.rst Related to: commit ad025f8e46f3 ("PCI/sysfs: Use sysfs_emit() and sysfs_emit_at() in "show" functions") Signed-off-by: Krzysztof Wilczyński Reviewed-by: Logan Gunthorpe --- Changes in v2: None. Changes in v3: Added Logan Gunthorpe's "Reviewed-by". Changes in v4: Separated and squashed all the trivial sysfs_emit()/sysfs_emit_at() changes into a single patch as per Bjorn Helgaas' request. Carried Logan Gunthorpe's "Reviewed-by" over. drivers/pci/hotplug/pci_hotplug_core.c | 8 +++--- drivers/pci/hotplug/rpadlpar_sysfs.c | 4 +-- drivers/pci/hotplug/shpchp_sysfs.c | 38 ++++++++++++++------------ drivers/pci/iov.c | 12 ++++---- drivers/pci/msi.c | 8 +++--- drivers/pci/p2pdma.c | 7 ++--- drivers/pci/pci-label.c | 6 ++-- drivers/pci/pci.c | 2 +- drivers/pci/pcie/aer.c | 20 ++++++++------ drivers/pci/pcie/aspm.c | 4 +-- drivers/pci/slot.c | 18 ++++++------ drivers/pci/switch/switchtec.c | 18 ++++++------ 12 files changed, 75 insertions(+), 70 deletions(-) diff --git a/drivers/pci/hotplug/pci_hotplug_core.c b/drivers/pci/hotplug/pci_hotplug_core.c index 5ac31f683b85..058d5937d8a9 100644 --- a/drivers/pci/hotplug/pci_hotplug_core.c +++ b/drivers/pci/hotplug/pci_hotplug_core.c @@ -73,7 +73,7 @@ static ssize_t power_read_file(struct pci_slot *pci_slot, char *buf) if (retval) return retval; - return sprintf(buf, "%d\n", value); + return sysfs_emit(buf, "%d\n", value); } static ssize_t power_write_file(struct pci_slot *pci_slot, const char *buf, @@ -130,7 +130,7 @@ static ssize_t attention_read_file(struct pci_slot *pci_slot, char *buf) if (retval) return retval; - return sprintf(buf, "%d\n", value); + return sysfs_emit(buf, "%d\n", value); } static ssize_t attention_write_file(struct pci_slot *pci_slot, const char *buf, @@ -175,7 +175,7 @@ static ssize_t latch_read_file(struct pci_slot *pci_slot, char *buf) if (retval) return retval; - return sprintf(buf, "%d\n", value); + return sysfs_emit(buf, "%d\n", value); } static struct pci_slot_attribute hotplug_slot_attr_latch = { @@ -192,7 +192,7 @@ static ssize_t presence_read_file(struct pci_slot *pci_slot, char *buf) if (retval) return retval; - return sprintf(buf, "%d\n", value); + return sysfs_emit(buf, "%d\n", value); } static struct pci_slot_attribute hotplug_slot_attr_presence = { diff --git a/drivers/pci/hotplug/rpadlpar_sysfs.c b/drivers/pci/hotplug/rpadlpar_sysfs.c index dbfa0b55d31a..068b7810a574 100644 --- a/drivers/pci/hotplug/rpadlpar_sysfs.c +++ b/drivers/pci/hotplug/rpadlpar_sysfs.c @@ -50,7 +50,7 @@ static ssize_t add_slot_store(struct kobject *kobj, struct kobj_attribute *attr, static ssize_t add_slot_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return sprintf(buf, "0\n"); + return sysfs_emit(buf, "0\n"); } static ssize_t remove_slot_store(struct kobject *kobj, @@ -80,7 +80,7 @@ static ssize_t remove_slot_store(struct kobject *kobj, static ssize_t remove_slot_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return sprintf(buf, "0\n"); + return sysfs_emit(buf, "0\n"); } static struct kobj_attribute add_slot_attr = diff --git a/drivers/pci/hotplug/shpchp_sysfs.c b/drivers/pci/hotplug/shpchp_sysfs.c index 45658bb5c554..64beed7a26be 100644 --- a/drivers/pci/hotplug/shpchp_sysfs.c +++ b/drivers/pci/hotplug/shpchp_sysfs.c @@ -24,50 +24,54 @@ static ssize_t show_ctrl(struct device *dev, struct device_attribute *attr, char *buf) { struct pci_dev *pdev; - char *out = buf; int index, busnr; struct resource *res; struct pci_bus *bus; + size_t len = 0; pdev = to_pci_dev(dev); bus = pdev->subordinate; - out += sprintf(buf, "Free resources: memory\n"); + len += sysfs_emit_at(buf, len, "Free resources: memory\n"); pci_bus_for_each_resource(bus, res, index) { if (res && (res->flags & IORESOURCE_MEM) && !(res->flags & IORESOURCE_PREFETCH)) { - out += sprintf(out, "start = %8.8llx, length = %8.8llx\n", - (unsigned long long)res->start, - (unsigned long long)resource_size(res)); + len += sysfs_emit_at(buf, len, + "start = %8.8llx, length = %8.8llx\n", + (unsigned long long)res->start, + (unsigned long long)resource_size(res)); } } - out += sprintf(out, "Free resources: prefetchable memory\n"); + len += sysfs_emit_at(buf, len, "Free resources: prefetchable memory\n"); pci_bus_for_each_resource(bus, res, index) { if (res && (res->flags & IORESOURCE_MEM) && (res->flags & IORESOURCE_PREFETCH)) { - out += sprintf(out, "start = %8.8llx, length = %8.8llx\n", - (unsigned long long)res->start, - (unsigned long long)resource_size(res)); + len += sysfs_emit_at(buf, len, + "start = %8.8llx, length = %8.8llx\n", + (unsigned long long)res->start, + (unsigned long long)resource_size(res)); } } - out += sprintf(out, "Free resources: IO\n"); + len += sysfs_emit_at(buf, len, "Free resources: IO\n"); pci_bus_for_each_resource(bus, res, index) { if (res && (res->flags & IORESOURCE_IO)) { - out += sprintf(out, "start = %8.8llx, length = %8.8llx\n", - (unsigned long long)res->start, - (unsigned long long)resource_size(res)); + len += sysfs_emit_at(buf, len, + "start = %8.8llx, length = %8.8llx\n", + (unsigned long long)res->start, + (unsigned long long)resource_size(res)); } } - out += sprintf(out, "Free resources: bus numbers\n"); + len += sysfs_emit_at(buf, len, "Free resources: bus numbers\n"); for (busnr = bus->busn_res.start; busnr <= bus->busn_res.end; busnr++) { if (!pci_find_bus(pci_domain_nr(bus), busnr)) break; } if (busnr < bus->busn_res.end) - out += sprintf(out, "start = %8.8x, length = %8.8x\n", - busnr, (int)(bus->busn_res.end - busnr)); + len += sysfs_emit_at(buf, len, + "start = %8.8x, length = %8.8x\n", + busnr, (int)(bus->busn_res.end - busnr)); - return out - buf; + return len; } static DEVICE_ATTR(ctrl, S_IRUGO, show_ctrl, NULL); diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index afc06e6ce115..a71258347323 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -346,7 +346,7 @@ static ssize_t sriov_totalvfs_show(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); - return sprintf(buf, "%u\n", pci_sriov_get_totalvfs(pdev)); + return sysfs_emit(buf, "%u\n", pci_sriov_get_totalvfs(pdev)); } static ssize_t sriov_numvfs_show(struct device *dev, @@ -361,7 +361,7 @@ static ssize_t sriov_numvfs_show(struct device *dev, num_vfs = pdev->sriov->num_VFs; device_unlock(&pdev->dev); - return sprintf(buf, "%u\n", num_vfs); + return sysfs_emit(buf, "%u\n", num_vfs); } /* @@ -435,7 +435,7 @@ static ssize_t sriov_offset_show(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); - return sprintf(buf, "%u\n", pdev->sriov->offset); + return sysfs_emit(buf, "%u\n", pdev->sriov->offset); } static ssize_t sriov_stride_show(struct device *dev, @@ -444,7 +444,7 @@ static ssize_t sriov_stride_show(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); - return sprintf(buf, "%u\n", pdev->sriov->stride); + return sysfs_emit(buf, "%u\n", pdev->sriov->stride); } static ssize_t sriov_vf_device_show(struct device *dev, @@ -453,7 +453,7 @@ static ssize_t sriov_vf_device_show(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); - return sprintf(buf, "%x\n", pdev->sriov->vf_device); + return sysfs_emit(buf, "%x\n", pdev->sriov->vf_device); } static ssize_t sriov_drivers_autoprobe_show(struct device *dev, @@ -462,7 +462,7 @@ static ssize_t sriov_drivers_autoprobe_show(struct device *dev, { struct pci_dev *pdev = to_pci_dev(dev); - return sprintf(buf, "%u\n", pdev->sriov->drivers_autoprobe); + return sysfs_emit(buf, "%u\n", pdev->sriov->drivers_autoprobe); } static ssize_t sriov_drivers_autoprobe_store(struct device *dev, diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 217dc9f0231f..9232255c8515 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -464,11 +464,11 @@ static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr, return retval; entry = irq_get_msi_desc(irq); - if (entry) - return sprintf(buf, "%s\n", - entry->msi_attrib.is_msix ? "msix" : "msi"); + if (!entry) + return -ENODEV; - return -ENODEV; + return sysfs_emit(buf, "%s\n", + entry->msi_attrib.is_msix ? "msix" : "msi"); } static int populate_msi_sysfs(struct pci_dev *pdev) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 196382630363..a1351b3e2c4c 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -53,7 +53,7 @@ static ssize_t size_show(struct device *dev, struct device_attribute *attr, if (pdev->p2pdma->pool) size = gen_pool_size(pdev->p2pdma->pool); - return scnprintf(buf, PAGE_SIZE, "%zd\n", size); + return sysfs_emit(buf, "%zd\n", size); } static DEVICE_ATTR_RO(size); @@ -66,7 +66,7 @@ static ssize_t available_show(struct device *dev, struct device_attribute *attr, if (pdev->p2pdma->pool) avail = gen_pool_avail(pdev->p2pdma->pool); - return scnprintf(buf, PAGE_SIZE, "%zd\n", avail); + return sysfs_emit(buf, "%zd\n", avail); } static DEVICE_ATTR_RO(available); @@ -75,8 +75,7 @@ static ssize_t published_show(struct device *dev, struct device_attribute *attr, { struct pci_dev *pdev = to_pci_dev(dev); - return scnprintf(buf, PAGE_SIZE, "%d\n", - pdev->p2pdma->p2pmem_published); + return sysfs_emit(buf, "%d\n", pdev->p2pdma->p2pmem_published); } static DEVICE_ATTR_RO(published); diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c index c32f3b7540e8..311dd48e2881 100644 --- a/drivers/pci/pci-label.c +++ b/drivers/pci/pci-label.c @@ -175,11 +175,11 @@ static int dsm_get_label(struct device *dev, char *buf, * this entry must return a null string. */ if (attr == ACPI_ATTR_INDEX_SHOW) { - scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value); + sysfs_emit(buf, "%llu\n", tmp->integer.value); } else if (attr == ACPI_ATTR_LABEL_SHOW) { if (tmp[1].type == ACPI_TYPE_STRING) - scnprintf(buf, PAGE_SIZE, "%s\n", - tmp[1].string.pointer); + sysfs_emit(buf, "%s\n", + tmp[1].string.pointer); else if (tmp[1].type == ACPI_TYPE_BUFFER) dsm_label_utf16s_to_utf8s(tmp + 1, buf); } diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b717680377a9..5ed316ea5831 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6439,7 +6439,7 @@ static ssize_t resource_alignment_show(struct bus_type *bus, char *buf) spin_lock(&resource_alignment_lock); if (resource_alignment_param) - count = scnprintf(buf, PAGE_SIZE, "%s", resource_alignment_param); + count = sysfs_emit(buf, "%s", resource_alignment_param); spin_unlock(&resource_alignment_lock); /* diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index ec943cee5ecc..40ef7bed7a77 100644 --- a/drivers/pci/pcie/aer.c +++ b/drivers/pci/pcie/aer.c @@ -529,21 +529,23 @@ static const char *aer_agent_string[] = { char *buf) \ { \ unsigned int i; \ - char *str = buf; \ struct pci_dev *pdev = to_pci_dev(dev); \ u64 *stats = pdev->aer_stats->stats_array; \ + size_t len = 0; \ \ for (i = 0; i < ARRAY_SIZE(strings_array); i++) { \ if (strings_array[i]) \ - str += sprintf(str, "%s %llu\n", \ - strings_array[i], stats[i]); \ + len += sysfs_emit_at(buf, len, "%s %llu\n", \ + strings_array[i], \ + stats[i]); \ else if (stats[i]) \ - str += sprintf(str, #stats_array "_bit[%d] %llu\n",\ - i, stats[i]); \ + len += sysfs_emit_at(buf, len, \ + #stats_array "_bit[%d] %llu\n",\ + i, stats[i]); \ } \ - str += sprintf(str, "TOTAL_%s %llu\n", total_string, \ - pdev->aer_stats->total_field); \ - return str-buf; \ + len += sysfs_emit_at(buf, len, "TOTAL_%s %llu\n", total_string, \ + pdev->aer_stats->total_field); \ + return len; \ } \ static DEVICE_ATTR_RO(name) @@ -563,7 +565,7 @@ aer_stats_dev_attr(aer_dev_nonfatal, dev_nonfatal_errs, char *buf) \ { \ struct pci_dev *pdev = to_pci_dev(dev); \ - return sprintf(buf, "%llu\n", pdev->aer_stats->field); \ + return sysfs_emit(buf, "%llu\n", pdev->aer_stats->field); \ } \ static DEVICE_ATTR_RO(name) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index ac0557a305af..013a47f587ce 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1208,7 +1208,7 @@ static ssize_t aspm_attr_show_common(struct device *dev, struct pci_dev *pdev = to_pci_dev(dev); struct pcie_link_state *link = pcie_aspm_get_link(pdev); - return sprintf(buf, "%d\n", (link->aspm_enabled & state) ? 1 : 0); + return sysfs_emit(buf, "%d\n", (link->aspm_enabled & state) ? 1 : 0); } static ssize_t aspm_attr_store_common(struct device *dev, @@ -1265,7 +1265,7 @@ static ssize_t clkpm_show(struct device *dev, struct pci_dev *pdev = to_pci_dev(dev); struct pcie_link_state *link = pcie_aspm_get_link(pdev); - return sprintf(buf, "%d\n", link->clkpm_enabled); + return sysfs_emit(buf, "%d\n", link->clkpm_enabled); } static ssize_t clkpm_store(struct device *dev, diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c index d627dd9179b4..751a26668e3a 100644 --- a/drivers/pci/slot.c +++ b/drivers/pci/slot.c @@ -39,19 +39,19 @@ static const struct sysfs_ops pci_slot_sysfs_ops = { static ssize_t address_read_file(struct pci_slot *slot, char *buf) { if (slot->number == 0xff) - return sprintf(buf, "%04x:%02x\n", - pci_domain_nr(slot->bus), - slot->bus->number); - else - return sprintf(buf, "%04x:%02x:%02x\n", - pci_domain_nr(slot->bus), - slot->bus->number, - slot->number); + return sysfs_emit(buf, "%04x:%02x\n", + pci_domain_nr(slot->bus), + slot->bus->number); + + return sysfs_emit(buf, "%04x:%02x:%02x\n", + pci_domain_nr(slot->bus), + slot->bus->number, + slot->number); } static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf) { - return sprintf(buf, "%s\n", pci_speed_string(speed)); + return sysfs_emit(buf, "%s\n", pci_speed_string(speed)); } static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf) diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c index ba52459928f7..0b301f8be9ed 100644 --- a/drivers/pci/switch/switchtec.c +++ b/drivers/pci/switch/switchtec.c @@ -280,7 +280,7 @@ static ssize_t device_version_show(struct device *dev, ver = ioread32(&stdev->mmio_sys_info->device_version); - return sprintf(buf, "%x\n", ver); + return sysfs_emit(buf, "%x\n", ver); } static DEVICE_ATTR_RO(device_version); @@ -292,7 +292,7 @@ static ssize_t fw_version_show(struct device *dev, ver = ioread32(&stdev->mmio_sys_info->firmware_version); - return sprintf(buf, "%08x\n", ver); + return sysfs_emit(buf, "%08x\n", ver); } static DEVICE_ATTR_RO(fw_version); @@ -344,7 +344,7 @@ static ssize_t component_vendor_show(struct device *dev, /* component_vendor field not supported after gen3 */ if (stdev->gen != SWITCHTEC_GEN3) - return sprintf(buf, "none\n"); + return sysfs_emit(buf, "none\n"); return io_string_show(buf, &si->gen3.component_vendor, sizeof(si->gen3.component_vendor)); @@ -359,9 +359,9 @@ static ssize_t component_id_show(struct device *dev, /* component_id field not supported after gen3 */ if (stdev->gen != SWITCHTEC_GEN3) - return sprintf(buf, "none\n"); + return sysfs_emit(buf, "none\n"); - return sprintf(buf, "PM%04X\n", id); + return sysfs_emit(buf, "PM%04X\n", id); } static DEVICE_ATTR_RO(component_id); @@ -373,9 +373,9 @@ static ssize_t component_revision_show(struct device *dev, /* component_revision field not supported after gen3 */ if (stdev->gen != SWITCHTEC_GEN3) - return sprintf(buf, "255\n"); + return sysfs_emit(buf, "255\n"); - return sprintf(buf, "%d\n", rev); + return sysfs_emit(buf, "%d\n", rev); } static DEVICE_ATTR_RO(component_revision); @@ -384,7 +384,7 @@ static ssize_t partition_show(struct device *dev, { struct switchtec_dev *stdev = to_stdev(dev); - return sprintf(buf, "%d\n", stdev->partition); + return sysfs_emit(buf, "%d\n", stdev->partition); } static DEVICE_ATTR_RO(partition); @@ -393,7 +393,7 @@ static ssize_t partition_count_show(struct device *dev, { struct switchtec_dev *stdev = to_stdev(dev); - return sprintf(buf, "%d\n", stdev->partition_count); + return sysfs_emit(buf, "%d\n", stdev->partition_count); } static DEVICE_ATTR_RO(partition_count); From patchwork Tue May 25 12:23:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= X-Patchwork-Id: 12278633 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48080C2B9F8 for ; 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Tue, 25 May 2021 05:24:23 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id u1sm14220258pfc.63.2021.05.25.05.24.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 05:24:23 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Logan Gunthorpe , Joe Perches , "Oliver O'Halloran" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Tyrel Datwyler , Russell Currey , Kurt Schwemmer , Vidya Sagar , Xiongfeng Wang , linux-pci@vger.kernel.org Subject: [PATCH v4 2/5] PCI/sysfs: Use return value from dsm_label_utf16s_to_utf8s() directly Date: Tue, 25 May 2021 12:23:58 +0000 Message-Id: <20210525122401.206136-2-kw@linux.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210525122401.206136-1-kw@linux.com> References: <20210525122401.206136-1-kw@linux.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Modify the function dsm_label_utf16s_to_utf8s() to directly return the number of bytes written into the buffer so that the strlen() used later to calculate the length of the buffer can be removed as it would no longer be needed. No functional change intended. Signed-off-by: Krzysztof Wilczyński Reviewed-by: Logan Gunthorpe --- Changes in v2: None. Changes in v3: None. Changes in v4: Separated this patch from other trivial sysfs_emit()/sysfs_emit_at() patches into a separate patch as per Bjorn Helgaas' request. Added Logan Gunthorpe's "Reviewed-by". drivers/pci/pci-label.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c index 311dd48e2881..000e169c7197 100644 --- a/drivers/pci/pci-label.c +++ b/drivers/pci/pci-label.c @@ -139,14 +139,17 @@ enum acpi_attr_enum { ACPI_ATTR_INDEX_SHOW, }; -static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) +static int dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) { int len; + len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer, obj->buffer.length, UTF16_LITTLE_ENDIAN, buf, PAGE_SIZE); buf[len] = '\n'; + + return len; } static int dsm_get_label(struct device *dev, char *buf, @@ -154,7 +157,7 @@ static int dsm_get_label(struct device *dev, char *buf, { acpi_handle handle = ACPI_HANDLE(dev); union acpi_object *obj, *tmp; - int len = -1; + int len = 0; if (!handle) return -1; @@ -175,20 +178,19 @@ static int dsm_get_label(struct device *dev, char *buf, * this entry must return a null string. */ if (attr == ACPI_ATTR_INDEX_SHOW) { - sysfs_emit(buf, "%llu\n", tmp->integer.value); + len = sysfs_emit(buf, "%llu\n", tmp->integer.value); } else if (attr == ACPI_ATTR_LABEL_SHOW) { if (tmp[1].type == ACPI_TYPE_STRING) - sysfs_emit(buf, "%s\n", - tmp[1].string.pointer); + len = sysfs_emit(buf, "%s\n", + tmp[1].string.pointer); else if (tmp[1].type == ACPI_TYPE_BUFFER) - dsm_label_utf16s_to_utf8s(tmp + 1, buf); + len = dsm_label_utf16s_to_utf8s(tmp + 1, buf); } - len = strlen(buf) > 0 ? strlen(buf) : -1; } ACPI_FREE(obj); - return len; + return len > 0 ? len : -1; } static ssize_t label_show(struct device *dev, struct device_attribute *attr, From patchwork Tue May 25 12:23:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= X-Patchwork-Id: 12278635 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 576C7C2B9F8 for ; Tue, 25 May 2021 12:24:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 303B461409 for ; Tue, 25 May 2021 12:24:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232506AbhEYM0D (ORCPT ); Tue, 25 May 2021 08:26:03 -0400 Received: from mail-pl1-f176.google.com ([209.85.214.176]:38616 "EHLO mail-pl1-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232598AbhEYM0B (ORCPT ); Tue, 25 May 2021 08:26:01 -0400 Received: by mail-pl1-f176.google.com with SMTP id 69so16269592plc.5 for ; Tue, 25 May 2021 05:24:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=q0qIU0oiMxpyzvJd2lGzSmEaG/RIL/dlUB0R2VxtIxo=; b=jUQR+IgMkk+eNNihYu/eMAIL+z+9+rJCZBk6JJRNQ+LXKd2nqDHLkhrfY8jL5c/sNl g5NGfOentvu5hvhA1+eVx9RkDHou1FPEX/HvGQ1ESaoLc5hLVbop3PdC6MJ1Xz2Ojv0A k0xAzBPIemKhnP78xNI4t2PbZOH4jSFBIfjC77N4TM6HIx5eK19CSMJbSBMAH7BKZAZI 4Uqa4EIayiH1mz/jWKKuK8qSz/ThnqcOb2w/kzGEcRUDxqktfAJrDmA0XxmfUPkEdsR/ CPyHbjvoQ0DZfOWRPYZlbZR0mbrvHCppemw3rmUdENoVP7vF728jem/1gCSrIOTLZ+Qf Xj6g== X-Gm-Message-State: AOAM533S0RSLYcmjyDePxJCpgDq+l4E+RenHoKCKH5L0Ec1/d6LiGCN9 QjH6h4nARPTAGC7my6HJpBg= X-Google-Smtp-Source: ABdhPJzfPcQlcQbtoycP+3gBQmg91gdjk4gv86svlxHRgRk6Zn8Pz+ttvyglbgdrH4TYXX7CHt1h/A== X-Received: by 2002:a17:90b:4b0f:: with SMTP id lx15mr29295636pjb.184.1621945471982; Tue, 25 May 2021 05:24:31 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id u1sm14220258pfc.63.2021.05.25.05.24.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 05:24:31 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Logan Gunthorpe , Joe Perches , "Oliver O'Halloran" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Tyrel Datwyler , Russell Currey , Kurt Schwemmer , Vidya Sagar , Xiongfeng Wang , linux-pci@vger.kernel.org Subject: [PATCH v4 3/5] PCI/sysfs: Fix trailing newline handling of resource_alignment_param Date: Tue, 25 May 2021 12:23:59 +0000 Message-Id: <20210525122401.206136-3-kw@linux.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210525122401.206136-1-kw@linux.com> References: <20210525122401.206136-1-kw@linux.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The value of the "resource_alignment" can be specified using a kernel command-line argument (using the "pci=resource_alignment=") or through the corresponding sysfs object under the /sys/bus/pci path. Currently, when the value is set via the kernel command-line argument, and then subsequently accessed through sysfs object, the value read back will not be correct, as per: # grep -oE 'pci=resource_alignment.+' /proc/cmdline pci=resource_alignment=20@00:1f.2 # cat /sys/bus/pci/resource_alignment 20@00:1f. This is also true when the value is set through the sysfs object, but the trailing newline has not been included, as per: # echo -n 20@00:1f.2 > /sys/bus/pci/resource_alignment # cat /sys/bus/pci/resource_alignment 20@00:1f. When the value set through the sysfs object includes the trailing newline, then reading it back will work as intended, as per: # echo 20@00:1f.2 > /sys/bus/pci/resource_alignment # cat /sys/bus/pci/resource_alignment 20@00:1f.2 To fix this inconsistency, append a trailing newline in the show() function and strip the trailing line in the store() function if one is present. Also, allow for the value previously set using either a command-line argument or through the sysfs object to be cleared at run-time. Fixes: e499081da1a2 ("PCI: Force trailing new line to resource_alignment_param in sysfs") Signed-off-by: Krzysztof Wilczyński Reviewed-by: Logan Gunthorpe --- Changes in v2: None. Changes in v3: Added Logan Gunthorpe's "Reviewed-by". Changes in v4: None. drivers/pci/pci.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 5ed316ea5831..7cde86bdcc8e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6439,34 +6439,37 @@ static ssize_t resource_alignment_show(struct bus_type *bus, char *buf) spin_lock(&resource_alignment_lock); if (resource_alignment_param) - count = sysfs_emit(buf, "%s", resource_alignment_param); + count = sysfs_emit(buf, "%s\n", resource_alignment_param); spin_unlock(&resource_alignment_lock); - /* - * When set by the command line, resource_alignment_param will not - * have a trailing line feed, which is ugly. So conditionally add - * it here. - */ - if (count >= 2 && buf[count - 2] != '\n' && count < PAGE_SIZE - 1) { - buf[count - 1] = '\n'; - buf[count++] = 0; - } - return count; } static ssize_t resource_alignment_store(struct bus_type *bus, const char *buf, size_t count) { - char *param = kstrndup(buf, count, GFP_KERNEL); + char *param, *old, *end; + param = kstrndup(buf, count, GFP_KERNEL); if (!param) return -ENOMEM; + end = strchr(param, '\n'); + if (end) + *end = '\0'; + spin_lock(&resource_alignment_lock); - kfree(resource_alignment_param); - resource_alignment_param = param; + old = resource_alignment_param; + if (strlen(param)) { + resource_alignment_param = param; + } else { + kfree(resource_alignment_param); + resource_alignment_param = NULL; + } spin_unlock(&resource_alignment_lock); + + kfree(old); + return count; } From patchwork Tue May 25 12:24:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= X-Patchwork-Id: 12278637 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D117C2B9F8 for ; Tue, 25 May 2021 12:24:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 600DA61409 for ; Tue, 25 May 2021 12:24:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232230AbhEYM0K (ORCPT ); Tue, 25 May 2021 08:26:10 -0400 Received: from mail-pf1-f177.google.com ([209.85.210.177]:35790 "EHLO mail-pf1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232518AbhEYM0J (ORCPT ); Tue, 25 May 2021 08:26:09 -0400 Received: by mail-pf1-f177.google.com with SMTP id g18so21811366pfr.2 for ; Tue, 25 May 2021 05:24:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=gTzsrXViPTWjnX/pI+VkTtQrGiMMsRJfFisasSRful4=; b=nXl6Pz0HN3Gl14aK6NTXQ5Nf/m2ncQyOKuA3rqbGooRv5xr3Nx5FMKmN0o8pIcnUHd x/016v3vWwCYHki1LWVpdCFWTVeFJJyIan1NJwCErEGiA272TRHHzr5fBq58rBWlvq0/ AIm2T8wgcxKFEqnMpBJ6YsD2V6ylYvQyb7Eng+gjAhGp9RKZ+X00PkO72N/7H4QEbDPN lpiaUaJRMK4Ga8ob0ldiIyr/LlY3ANpZNBkiZ9t4oTZq/uxd8/VI28MzeEzNGRD/HEVx PuQtGbrbWb8qdyorL7bkrsKwJG7QcDUaU2Lw9P42l7hn9vLwyx9Yo4UDBsHXI2VpcwvX IIxw== X-Gm-Message-State: AOAM530n0/R4s/kj1I+dPeKakPHNQrqJ5hV3JMF7NASXi1fqhuayDSbF 73d05CxLxgK6RItAaegNw8w= X-Google-Smtp-Source: ABdhPJyqYRfJWniGgiedWT5TOYKvtUMhbWdrEkDIspDmSmZzgOenCcrCjWJhXh97Brb4v7cG9hmFLA== X-Received: by 2002:a63:2307:: with SMTP id j7mr11207277pgj.20.1621945480189; Tue, 25 May 2021 05:24:40 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id u1sm14220258pfc.63.2021.05.25.05.24.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 05:24:39 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Logan Gunthorpe , Joe Perches , "Oliver O'Halloran" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Tyrel Datwyler , Russell Currey , Kurt Schwemmer , Vidya Sagar , Xiongfeng Wang , linux-pci@vger.kernel.org Subject: [PATCH v4 4/5] PCI/sysfs: Add missing trailing newline to devspec_show() Date: Tue, 25 May 2021 12:24:00 +0000 Message-Id: <20210525122401.206136-4-kw@linux.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210525122401.206136-1-kw@linux.com> References: <20210525122401.206136-1-kw@linux.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org At the moment, when the value of the "devspec" sysfs object is read from the user space there will be no newline present, and the utilities such as the "cat" command won't display the result of the read correctly in a shell, as the trailing newline is currently missing. To fix this, append a newline character in the show() function. Signed-off-by: Krzysztof Wilczyński Reviewed-by: Logan Gunthorpe --- Changes in v2: None. Changes in v3: Added Logan Gunthorpe's "Reviewed-by". Changes in v4: None. drivers/pci/pci-sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index beb8d1f4fafe..5d63df7c1820 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -537,7 +537,7 @@ static ssize_t devspec_show(struct device *dev, if (np == NULL) return 0; - return sysfs_emit(buf, "%pOF", np); + return sysfs_emit(buf, "%pOF\n", np); } static DEVICE_ATTR_RO(devspec); #endif From patchwork Tue May 25 12:24:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= X-Patchwork-Id: 12278639 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 857A8C2B9F8 for ; Tue, 25 May 2021 12:24:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 63C60613F5 for ; Tue, 25 May 2021 12:24:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232518AbhEYM0T (ORCPT ); Tue, 25 May 2021 08:26:19 -0400 Received: from mail-pg1-f172.google.com ([209.85.215.172]:41757 "EHLO mail-pg1-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232504AbhEYM0T (ORCPT ); Tue, 25 May 2021 08:26:19 -0400 Received: by mail-pg1-f172.google.com with SMTP id r1so7751181pgk.8 for ; Tue, 25 May 2021 05:24:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=F6bpNTp63J2JCwxOjLKFQTUbwufk/UzqLJ7gX6xEOkI=; b=tpkbywUqgcV1WCwhdg9KbYM+4TszPN4gBlmQN8xhnDS5M7t3Eu/DWrBr4J0P2VkVz6 fYRXL6C/7iIFEFiFdJMDn5apUQwR2pEX5wi7dmVOADkLx764bQV6dVAIpcrcY+vStz9h wVTUhGsysX2hgL3y/6ZrSpxmgrz+dh0JzHyOfOCvJaht+j6NpR6NN/aBBZwhe71p67FI WOt/y1c0qDGTXNE8mJkw//fVPbQO/AXFR7Ne9s4jZUTRWs0feRZGr7nhxbqtTkhgUBpz d+Ui72xtZd4guvDKGmoil+SB5k99jjUQ9B54C55AjVlcNf3xFPN72Mu0R3iKL6CO71+D Dg4Q== X-Gm-Message-State: AOAM532Aw70c3sPGIouOf++TiPjC4yujmfXDoztIzwIqh7tUIgvDGKTN 39bmKYMDVbfTZ7skVz6vmO0ovHhBTGgT4g== X-Google-Smtp-Source: ABdhPJyOgfBlKeuhzFjGqOxDN1Rj1C0L6TBW5Aojc3oqYI2dLxzJd9OxPjj+Rv5wRLA3mK3kKufosg== X-Received: by 2002:a05:6a00:1992:b029:2df:b93b:49a with SMTP id d18-20020a056a001992b02902dfb93b049amr29793945pfl.11.1621945488345; Tue, 25 May 2021 05:24:48 -0700 (PDT) Received: from workstation.lan ([95.155.85.46]) by smtp.gmail.com with ESMTPSA id u1sm14220258pfc.63.2021.05.25.05.24.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 May 2021 05:24:48 -0700 (PDT) From: =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= To: Bjorn Helgaas Cc: Logan Gunthorpe , Joe Perches , "Oliver O'Halloran" , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Tyrel Datwyler , Russell Currey , Kurt Schwemmer , Vidya Sagar , Xiongfeng Wang , linux-pci@vger.kernel.org Subject: [PATCH v4 5/5] PCI/sysfs: Only show value when driver_override is not NULL Date: Tue, 25 May 2021 12:24:01 +0000 Message-Id: <20210525122401.206136-5-kw@linux.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210525122401.206136-1-kw@linux.com> References: <20210525122401.206136-1-kw@linux.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Only expose the value of the "driver_override" variable through the corresponding sysfs object when a value is actually set. Signed-off-by: Krzysztof Wilczyński Reviewed-by: Logan Gunthorpe --- Changes in v2: None. Changes in v3: Added Logan Gunthorpe's "Reviewed-by". Changes in v4: None. drivers/pci/pci-sysfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 5d63df7c1820..4e9f582ca10f 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -580,10 +580,11 @@ static ssize_t driver_override_show(struct device *dev, struct device_attribute *attr, char *buf) { struct pci_dev *pdev = to_pci_dev(dev); - ssize_t len; + ssize_t len = 0; device_lock(dev); - len = sysfs_emit(buf, "%s\n", pdev->driver_override); + if (pdev->driver_override) + len = sysfs_emit(buf, "%s\n", pdev->driver_override); device_unlock(dev); return len; }