| Message ID | iwlwifi.20220128142706.cc51e6a6d635.I4b74a082eb8d89f9e4f556a27c4339c15444dc6c@changeid (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 44bf7c4667efe10390aa59eda39833a9a0439b5b |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | iwlwifi: fixes intended for v5.17 2022-01-28 | expand |
Luca Coelho <luca@coelho.fi> writes: > From: Emmanuel Grumbach <emmanuel.grumbach@intel.com> > > The shared area is a DMA memory allocated in the host and > mapped so that the host and the CSME firmware can > exchange data. It is mapped through a dedicated PCI device > that is driven by the mei bus driver. > > The bus driver is in charge of allocating and mapping this > memory. It also needs to configure the CSME firmware with > a specific set of commands, so that the CSME firmware will > know that this memory is meant to be used by its internal > WLAN module. > > For this, the CSME firmware first needs to completely > initialize its WLAN module and only then get the mapping > request. > > The problem is that the mei bus enumeration completes > before the WLAN is completely ready. This means that > the WLAN module's initialization is racing with iwlmei's > allocation and mapping flow. > > Testing showed a problem in resume flows where iwlmei > was too fast and the DMA mapping failed. > > Add a retry mechanism to make sure that we will succeed > to map the memory. > > Fixes: 2da4366f9e2c ("iwlwifi: mei: add the driver to allow cooperation with CSME") > Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> > Fixes: bcbddc4f9d02 ("iwlwifi: mei: wait before mapping the shared area") I'll move the latter Fixes before s-o-b tag. > - /* > - * The CSME firmware needs to boot the internal WLAN client. Wait here > - * so that the DMA map request will succeed. > - */ > - msleep(20); > + do { > + ret = iwl_mei_alloc_shared_mem(cldev); > + if (!ret) > + break; > + /* > + * The CSME firmware needs to boot the internal WLAN client. > + * This can take time in certain configurations (usually > + * upon resume and when the whole CSME firmware is shut down > + * during suspend). > + * > + * Wait a bit before retrying and hope we'll succeed next time. > + */ > > - ret = iwl_mei_alloc_shared_mem(cldev); > - if (ret) > + dev_dbg(&cldev->dev, > + "Couldn't allocate the shared memory: %d, attempt %d / %d\n", > + ret, alloc_retry, ALLOC_SHARED_MEM_RETRY_MAX_NUM); > + msleep(100); > + alloc_retry--; > + } while (alloc_retry); Nitpicking, but this could have been: while (alloc_retry--); But no need to resend because of this.
diff --git a/drivers/net/wireless/intel/iwlwifi/mei/main.c b/drivers/net/wireless/intel/iwlwifi/mei/main.c index d9733aaf6f6e..6cc5553027a0 100644 --- a/drivers/net/wireless/intel/iwlwifi/mei/main.c +++ b/drivers/net/wireless/intel/iwlwifi/mei/main.c @@ -229,8 +229,6 @@ static int iwl_mei_alloc_shared_mem(struct mei_cl_device *cldev) if (IS_ERR(mem->ctrl)) { int ret = PTR_ERR(mem->ctrl); - dev_err(&cldev->dev, "Couldn't allocate the shared memory: %d\n", - ret); mem->ctrl = NULL; return ret; @@ -1784,6 +1782,8 @@ static void iwl_mei_dbgfs_unregister(struct iwl_mei *mei) {} #endif /* CONFIG_DEBUG_FS */ +#define ALLOC_SHARED_MEM_RETRY_MAX_NUM 3 + /* * iwl_mei_probe - the probe function called by the mei bus enumeration * @@ -1795,6 +1795,7 @@ static void iwl_mei_dbgfs_unregister(struct iwl_mei *mei) {} static int iwl_mei_probe(struct mei_cl_device *cldev, const struct mei_cl_device_id *id) { + int alloc_retry = ALLOC_SHARED_MEM_RETRY_MAX_NUM; struct iwl_mei *mei; int ret; @@ -1812,15 +1813,31 @@ static int iwl_mei_probe(struct mei_cl_device *cldev, mei_cldev_set_drvdata(cldev, mei); mei->cldev = cldev; - /* - * The CSME firmware needs to boot the internal WLAN client. Wait here - * so that the DMA map request will succeed. - */ - msleep(20); + do { + ret = iwl_mei_alloc_shared_mem(cldev); + if (!ret) + break; + /* + * The CSME firmware needs to boot the internal WLAN client. + * This can take time in certain configurations (usually + * upon resume and when the whole CSME firmware is shut down + * during suspend). + * + * Wait a bit before retrying and hope we'll succeed next time. + */ - ret = iwl_mei_alloc_shared_mem(cldev); - if (ret) + dev_dbg(&cldev->dev, + "Couldn't allocate the shared memory: %d, attempt %d / %d\n", + ret, alloc_retry, ALLOC_SHARED_MEM_RETRY_MAX_NUM); + msleep(100); + alloc_retry--; + } while (alloc_retry); + + if (ret) { + dev_err(&cldev->dev, "Couldn't allocate the shared memory: %d\n", + ret); goto free; + } iwl_mei_init_shared_mem(mei);