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[149.200.78.10]) by smtp.gmail.com with ESMTPSA id a101sm12083131edf.76.2020.08.01.05.24.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 01 Aug 2020 05:24:34 -0700 (PDT) From: "Saheed O. Bolarinwa" To: helgaas@kernel.org, Bartosz Golaszewski , Linus Walleij Cc: "Saheed O. Bolarinwa" , bjorn@helgaas.com, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org Subject: [RFC PATCH 08/17] gpio: Drop uses of pci_read_config_*() return value Date: Sat, 1 Aug 2020 13:24:37 +0200 Message-Id: <20200801112446.149549-9-refactormyself@gmail.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20200801112446.149549-1-refactormyself@gmail.com> References: <20200801112446.149549-1-refactormyself@gmail.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org The return value of pci_read_config_*() may not indicate a device error. However, the value read by these functions is more likely to indicate this kind of error. This presents two overlapping ways of reporting errors and complicates error checking. It is possible to move to one single way of checking for error if the dependency on the return value of these functions is removed, then it can later be made to return void. Remove all uses of the return value of pci_read_config_*(). Check the actual value read for ~0. In this case, ~0 is an invalid value thus it indicates some kind of error. Suggested-by: Bjorn Helgaas Signed-off-by: Saheed O. Bolarinwa --- drivers/gpio/gpio-amd8111.c | 7 +++++-- drivers/gpio/gpio-rdc321x.c | 21 ++++++++++++--------- 2 files changed, 17 insertions(+), 11 deletions(-) diff --git a/drivers/gpio/gpio-amd8111.c b/drivers/gpio/gpio-amd8111.c index fdcebe59510d..7b9882380cbc 100644 --- a/drivers/gpio/gpio-amd8111.c +++ b/drivers/gpio/gpio-amd8111.c @@ -198,9 +198,12 @@ static int __init amd_gpio_init(void) goto out; found: - err = pci_read_config_dword(pdev, 0x58, &gp.pmbase); - if (err) + pci_read_config_dword(pdev, 0x58, &gp.pmbase); + if (gp.pmbase == (u32)~0) { + err = -ENODEV; goto out; + } + err = -EIO; gp.pmbase &= 0x0000FF00; if (gp.pmbase == 0) diff --git a/drivers/gpio/gpio-rdc321x.c b/drivers/gpio/gpio-rdc321x.c index 01ed2517e9fd..03f1ff07b844 100644 --- a/drivers/gpio/gpio-rdc321x.c +++ b/drivers/gpio/gpio-rdc321x.c @@ -85,10 +85,13 @@ static int rdc_gpio_config(struct gpio_chip *chip, gpch = gpiochip_get_data(chip); spin_lock(&gpch->lock); - err = pci_read_config_dword(gpch->sb_pdev, gpio < 32 ? - gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, ®); - if (err) + pci_read_config_dword(gpch->sb_pdev, + (gpio < 32) ? gpch->reg1_ctrl_base + : gpch->reg2_ctrl_base, ®); + if (reg == (u32)~0) { + err = -ENODEV; goto unlock; + } reg |= 1 << (gpio & 0x1f); @@ -166,17 +169,17 @@ static int rdc321x_gpio_probe(struct platform_device *pdev) /* This might not be, what others (BIOS, bootloader, etc.) wrote to these registers before, but it's a good guess. Still better than just using 0xffffffff. */ - err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, + pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, rdc321x_gpio_dev->reg1_data_base, &rdc321x_gpio_dev->data_reg[0]); - if (err) - return err; + if (rdc321x_gpio_dev->data_reg[0] == (u32)~0) + return -ENODEV; - err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, + pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, rdc321x_gpio_dev->reg2_data_base, &rdc321x_gpio_dev->data_reg[1]); - if (err) - return err; + if (rdc321x_gpio_dev->data_reg[1] == (u32)~0) + return -ENODEV; dev_info(&pdev->dev, "registering %d GPIOs\n", rdc321x_gpio_dev->chip.ngpio);