Messages in this thread | | | Date | Fri, 26 Aug 2011 10:45:47 -0700 | From | Greg KH <> | Subject | Re: [PATCH 8/9] gma500: frame buffer locking |
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On Fri, Aug 26, 2011 at 11:19:58AM +0100, Alan Cox wrote: > From: Alan Cox <alan@linux.intel.com> > > If we are the console then a printk can hit us with a spin lock held (and > in fact the kernel will do its best to take printing lock). > > In that case we cannot politely sleep when synching after an accelerated op > but must behave obnixously to be sure of getting the bits out. > > Signed-off-by: Alan Cox <alan@linux.intel.com> > --- > > drivers/staging/gma500/accel_2d.c | 10 ++++++---- > drivers/staging/gma500/psb_drv.c | 2 +- > drivers/staging/gma500/psb_drv.h | 2 +- > kernel/printk.c | 2 +- > 4 files changed, 9 insertions(+), 7 deletions(-) > > diff --git a/drivers/staging/gma500/accel_2d.c b/drivers/staging/gma500/accel_2d.c > index be92371..114b99a 100644 > --- a/drivers/staging/gma500/accel_2d.c > +++ b/drivers/staging/gma500/accel_2d.c > @@ -111,8 +111,9 @@ static int psbfb_2d_submit(struct drm_psb_private *dev_priv, uint32_t *cmdbuf, > int ret = 0; > int i; > unsigned submit_size; > + unsigned long flags; > > - mutex_lock(&dev_priv->mutex_2d); > + spin_lock_irqsave(&dev_priv->lock_2d, flags); > while (size > 0) { > submit_size = (size < 0x60) ? size : 0x60; > size -= submit_size; > @@ -127,7 +128,7 @@ static int psbfb_2d_submit(struct drm_psb_private *dev_priv, uint32_t *cmdbuf, > > (void)PSB_RSGX32(PSB_SGX_2D_SLAVE_PORT + i - 4); > } > - mutex_unlock(&dev_priv->mutex_2d); > + spin_unlock_irqrestore(&dev_priv->lock_2d, flags); > return ret; > } > > @@ -327,8 +328,9 @@ int psbfb_sync(struct fb_info *info) > struct drm_psb_private *dev_priv = dev->dev_private; > unsigned long _end = jiffies + DRM_HZ; > int busy = 0; > + unsigned long flags; > > - mutex_lock(&dev_priv->mutex_2d); > + spin_lock_irqsave(&dev_priv->lock_2d, flags); > /* > * First idle the 2D engine. > */ > @@ -357,7 +359,7 @@ int psbfb_sync(struct fb_info *info) > _PSB_C2B_STATUS_BUSY) != 0); > > out: > - mutex_unlock(&dev_priv->mutex_2d); > + spin_unlock_irqrestore(&dev_priv->lock_2d, flags); > return (busy) ? -EBUSY : 0; > } > > diff --git a/drivers/staging/gma500/psb_drv.c b/drivers/staging/gma500/psb_drv.c > index 34cf24a..9470af9 100644 > --- a/drivers/staging/gma500/psb_drv.c > +++ b/drivers/staging/gma500/psb_drv.c > @@ -228,7 +228,7 @@ static int psb_do_init(struct drm_device *dev) > > > spin_lock_init(&dev_priv->irqmask_lock); > - mutex_init(&dev_priv->mutex_2d); > + spin_lock_init(&dev_priv->lock_2d); > > PSB_WSGX32(0x00000000, PSB_CR_BIF_BANK0); > PSB_WSGX32(0x00000000, PSB_CR_BIF_BANK1); > diff --git a/drivers/staging/gma500/psb_drv.h b/drivers/staging/gma500/psb_drv.h > index 9cbb494..11d963a 100644 > --- a/drivers/staging/gma500/psb_drv.h > +++ b/drivers/staging/gma500/psb_drv.h > @@ -612,7 +612,7 @@ struct drm_psb_private { > void (*exit_idle)(struct drm_device *dev, u32 update_src); > > /* 2D acceleration */ > - struct mutex mutex_2d; > + spinlock_t lock_2d; > > /* FIXME: Arrays anyone ? */ > struct mdfld_dsi_encoder *encoder0; > diff --git a/kernel/printk.c b/kernel/printk.c > index e861488..af2eec8 100644 > --- a/kernel/printk.c > +++ b/kernel/printk.c > @@ -512,7 +512,7 @@ static void __call_console_drivers(unsigned start, unsigned end) > struct console *con; > > for_each_console(con) { > - if (exclusive_console && con != exclusive_console) > + if (0 && exclusive_console && con != exclusive_console) > continue; > if ((con->flags & CON_ENABLED) && con->write && > (cpu_online(smp_processor_id()) ||
Are you sure you want this in the tree? I don't feel comfortable making this fix just for one staging driver right now, do you?
greg k-h
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