| Message ID | 1428519599-31885-1-git-send-email-computersforpeace@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hello Brian, On 04/08/2015 08:59 PM, Brian Norris wrote: > When working on another SATA driver that uses libahci_platform, I > noticed an error in this driver; it tries to the the driver data for its > device, while libata also thinks it can set the driver data. See: > > ahci_platform_init_host() > -> ata_host_alloc_pinfo() > -> ata_host_alloc() > -> dev_set_drvdata() > > So instead of sticking the IP-specific platform data into drvdata, let's > use the plat_data variable that is reserved for this use. > > Signed-off-by: Brian Norris <computersforpeace@gmail.com> > Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com> > Cc: Maxime Coquelin <maxime.coquelin@st.com> > Cc: Patrice Chotard <patrice.chotard@st.com> > --- > This is ONLY compile tested; I don't have hardware to run. This looks like it > could have ramifications on suspend/resume support, and hot device removal > (e.g., sysfs unbind), so it might qualify as -stable, if someone can test it > > drivers/ata/ahci_st.c | 25 ++++++++++++++----------- > 1 file changed, 14 insertions(+), 11 deletions(-) > > Your patch looks sensible, thanks for spotting this issue. Peter, do you have the SATA setup in place to test Brian's patch? Once tested, you can add my: Acked-by: Maxime Coquelin <maxime.coquelin@st.com> Thanks, Maxime
Hello. On 4/8/2015 9:59 PM, Brian Norris wrote: > When working on another SATA driver that uses libahci_platform, I > noticed an error in this driver; it tries to the the driver data for its > device, while libata also thinks it can set the driver data. See: > ahci_platform_init_host() > -> ata_host_alloc_pinfo() > -> ata_host_alloc() > -> dev_set_drvdata() > So instead of sticking the IP-specific platform data into drvdata, let's > use the plat_data variable that is reserved for this use. > Signed-off-by: Brian Norris <computersforpeace@gmail.com> > Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com> > Cc: Maxime Coquelin <maxime.coquelin@st.com> > Cc: Patrice Chotard <patrice.chotard@st.com> > --- > This is ONLY compile tested; I don't have hardware to run. This looks like it > could have ramifications on suspend/resume support, and hot device removal > (e.g., sysfs unbind), so it might qualify as -stable, if someone can test it > drivers/ata/ahci_st.c | 25 ++++++++++++++----------- > 1 file changed, 14 insertions(+), 11 deletions(-) > diff --git a/drivers/ata/ahci_st.c b/drivers/ata/ahci_st.c > index bc971af262e7..2bd2375c2ab1 100644 > --- a/drivers/ata/ahci_st.c > +++ b/drivers/ata/ahci_st.c [...] > @@ -107,7 +108,9 @@ static void st_ahci_host_stop(struct ata_host *host) > > static int st_ahci_probe_resets(struct platform_device *pdev) > { > - struct st_ahci_drv_data *drv_data = platform_get_drvdata(pdev); > + struct ata_host *host = dev_get_drvdata(&pdev->dev); Why not just platform_get_drvdata()? [...] MBR, Sergei
Hi Maxime, On Thu, 09 Apr 2015, Maxime Coquelin wrote: > Hello Brian, > <snip> > > drivers/ata/ahci_st.c | 25 ++++++++++++++----------- > > 1 file changed, 14 insertions(+), 11 deletions(-) > > > > > > Your patch looks sensible, thanks for spotting this issue. > > Peter, do you have the SATA setup in place to test Brian's patch? Yes I can test, although not until Saturday as I only have remote access to the board today & tomorrow and the hard drive isn't plugged in. regards, Peter.
On Thu, Apr 09, 2015 at 12:34:02PM +0300, Sergei Shtylyov wrote: > Hello. > > On 4/8/2015 9:59 PM, Brian Norris wrote: > > >When working on another SATA driver that uses libahci_platform, I > >noticed an error in this driver; it tries to the the driver data for its > >device, while libata also thinks it can set the driver data. See: > > > ahci_platform_init_host() > > -> ata_host_alloc_pinfo() > > -> ata_host_alloc() > > -> dev_set_drvdata() > > >So instead of sticking the IP-specific platform data into drvdata, let's > >use the plat_data variable that is reserved for this use. > > >Signed-off-by: Brian Norris <computersforpeace@gmail.com> > >Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com> > >Cc: Maxime Coquelin <maxime.coquelin@st.com> > >Cc: Patrice Chotard <patrice.chotard@st.com> > >--- > >This is ONLY compile tested; I don't have hardware to run. This looks like it > >could have ramifications on suspend/resume support, and hot device removal > >(e.g., sysfs unbind), so it might qualify as -stable, if someone can test it > > > drivers/ata/ahci_st.c | 25 ++++++++++++++----------- > > 1 file changed, 14 insertions(+), 11 deletions(-) > > >diff --git a/drivers/ata/ahci_st.c b/drivers/ata/ahci_st.c > >index bc971af262e7..2bd2375c2ab1 100644 > >--- a/drivers/ata/ahci_st.c > >+++ b/drivers/ata/ahci_st.c > [...] > >@@ -107,7 +108,9 @@ static void st_ahci_host_stop(struct ata_host *host) > > > > static int st_ahci_probe_resets(struct platform_device *pdev) > > { > >- struct st_ahci_drv_data *drv_data = platform_get_drvdata(pdev); > >+ struct ata_host *host = dev_get_drvdata(&pdev->dev); > > Why not just platform_get_drvdata()? Just being consistent, as that's what the rest of the driver uses. It seems like it'd be easy to misconstrue dev_get_drvrdata(&pdev->dev) and platform_get_drvdata(pdev) as two different things (e.g., when grepping), when in fact they are the same. Seems like a needless source of potential confusion. Why should I use platform_get_drvdata()? (NB: I didn't notice at first that the driver already was using platform_get_drvdata(). I pretty much ignored anything that was already there, since it was all wrong anyway.) Anyway, I don't care either way, and in fact, I don't care about this driver much at all as I never expect to use it; I just noticed the defect when reading. Brian
On Thu, Apr 09, 2015 at 10:43:10AM +0100, Peter Griffin wrote: > Yes I can test, although not until Saturday as I only have remote > access to the board today & tomorrow and the hard drive isn't > plugged in. What's the status on this patch? Should I push it through for-4.1-fixes? Thanks.
Hi Tejun, On Fri, 17 Apr 2015, Tejun Heo wrote: > On Thu, Apr 09, 2015 at 10:43:10AM +0100, Peter Griffin wrote: > > Yes I can test, although not until Saturday as I only have remote > > access to the board today & tomorrow and the hard drive isn't > > plugged in. > > What's the status on this patch? Should I push it through > for-4.1-fixes? The layering violation which Brian identified does need fixing. However please don't take this patch as it currently is, as it causes a NULL ptr dereference. I can send an updated version in a moment which: - 1) Fixes the conflict you will get when applying it for v4.1 (due to my "st_configure_oob must be called after IP is clocked" patch). 2) Fixes the crash which this patch introduces. regards, Peter.
diff --git a/drivers/ata/ahci_st.c b/drivers/ata/ahci_st.c index bc971af262e7..2bd2375c2ab1 100644 --- a/drivers/ata/ahci_st.c +++ b/drivers/ata/ahci_st.c @@ -37,7 +37,6 @@ struct st_ahci_drv_data { struct reset_control *pwr; struct reset_control *sw_rst; struct reset_control *pwr_rst; - struct ahci_host_priv *hpriv; }; static void st_ahci_configure_oob(void __iomem *mmio) @@ -57,7 +56,9 @@ static void st_ahci_configure_oob(void __iomem *mmio) static int st_ahci_deassert_resets(struct device *dev) { - struct st_ahci_drv_data *drv_data = dev_get_drvdata(dev); + struct ata_host *host = dev_get_drvdata(dev); + struct ahci_host_priv *hpriv = host->private_data; + struct st_ahci_drv_data *drv_data = hpriv->plat_data; int err; if (drv_data->pwr) { @@ -68,7 +69,7 @@ static int st_ahci_deassert_resets(struct device *dev) } } - st_ahci_configure_oob(drv_data->hpriv->mmio); + st_ahci_configure_oob(hpriv->mmio); if (drv_data->sw_rst) { err = reset_control_deassert(drv_data->sw_rst); @@ -92,8 +93,8 @@ static int st_ahci_deassert_resets(struct device *dev) static void st_ahci_host_stop(struct ata_host *host) { struct ahci_host_priv *hpriv = host->private_data; + struct st_ahci_drv_data *drv_data = hpriv->plat_data; struct device *dev = host->dev; - struct st_ahci_drv_data *drv_data = dev_get_drvdata(dev); int err; if (drv_data->pwr) { @@ -107,7 +108,9 @@ static void st_ahci_host_stop(struct ata_host *host) static int st_ahci_probe_resets(struct platform_device *pdev) { - struct st_ahci_drv_data *drv_data = platform_get_drvdata(pdev); + struct ata_host *host = dev_get_drvdata(&pdev->dev); + struct ahci_host_priv *hpriv = host->private_data; + struct st_ahci_drv_data *drv_data = hpriv->plat_data; drv_data->pwr = devm_reset_control_get(&pdev->dev, "pwr-dwn"); if (IS_ERR(drv_data->pwr)) { @@ -161,8 +164,7 @@ static int st_ahci_probe(struct platform_device *pdev) hpriv = ahci_platform_get_resources(pdev); if (IS_ERR(hpriv)) return PTR_ERR(hpriv); - - drv_data->hpriv = hpriv; + hpriv->plat_data = drv_data; err = st_ahci_probe_resets(pdev); if (err) @@ -185,8 +187,9 @@ static int st_ahci_probe(struct platform_device *pdev) #ifdef CONFIG_PM_SLEEP static int st_ahci_suspend(struct device *dev) { - struct st_ahci_drv_data *drv_data = dev_get_drvdata(dev); - struct ahci_host_priv *hpriv = drv_data->hpriv; + struct ata_host *host = dev_get_drvdata(dev); + struct ahci_host_priv *hpriv = host->private_data; + struct st_ahci_drv_data *drv_data = hpriv->plat_data; int err; err = ahci_platform_suspend_host(dev); @@ -208,8 +211,8 @@ static int st_ahci_suspend(struct device *dev) static int st_ahci_resume(struct device *dev) { - struct st_ahci_drv_data *drv_data = dev_get_drvdata(dev); - struct ahci_host_priv *hpriv = drv_data->hpriv; + struct ata_host *host = dev_get_drvdata(dev); + struct ahci_host_priv *hpriv = host->private_data; int err; err = ahci_platform_enable_resources(hpriv);
When working on another SATA driver that uses libahci_platform, I noticed an error in this driver; it tries to the the driver data for its device, while libata also thinks it can set the driver data. See: ahci_platform_init_host() -> ata_host_alloc_pinfo() -> ata_host_alloc() -> dev_set_drvdata() So instead of sticking the IP-specific platform data into drvdata, let's use the plat_data variable that is reserved for this use. Signed-off-by: Brian Norris <computersforpeace@gmail.com> Cc: Srinivas Kandagatla <srinivas.kandagatla@gmail.com> Cc: Maxime Coquelin <maxime.coquelin@st.com> Cc: Patrice Chotard <patrice.chotard@st.com> --- This is ONLY compile tested; I don't have hardware to run. This looks like it could have ramifications on suspend/resume support, and hot device removal (e.g., sysfs unbind), so it might qualify as -stable, if someone can test it drivers/ata/ahci_st.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)