| Message ID | 1398904476-26200-7-git-send-email-s-anna@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Suman, On Thu, May 1, 2014 at 3:34 AM, Suman Anna <s-anna@ti.com> wrote: > The number of hwspinlocks are determined based on the value read > from the IP block's SYSSTATUS register. However, the module may > not be enabled and clocked, and the read may result in a bus error. > > This particular issue is seen rather easily on AM33XX, since the > module wakeup is software controlled, and it is disabled out of > reset. Make sure the module is enabled and clocked before reading > the SYSSTATUS register. This seems like a valid fix that is independent of this patch series. Feel free to submit it separately if you want, so we can get it merged. Thanks, Ohad. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Ohad, On 07/01/2014 07:51 AM, Ohad Ben-Cohen wrote: > Hi Suman, > > On Thu, May 1, 2014 at 3:34 AM, Suman Anna <s-anna@ti.com> wrote: >> The number of hwspinlocks are determined based on the value read >> from the IP block's SYSSTATUS register. However, the module may >> not be enabled and clocked, and the read may result in a bus error. >> >> This particular issue is seen rather easily on AM33XX, since the >> module wakeup is software controlled, and it is disabled out of >> reset. Make sure the module is enabled and clocked before reading >> the SYSSTATUS register. > > This seems like a valid fix that is independent of this patch series. > > Feel free to submit it separately if you want, so we can get it merged. > OK, I will submit this patch and Patch 7 separately. regards Suman -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index 9f56fb2..7764291 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -101,10 +101,29 @@ static int omap_hwspinlock_probe(struct platform_device *pdev) if (!io_base) return -ENOMEM; + /* + * make sure the module is enabled and clocked before reading + * the module SYSSTATUS register + */ + pm_runtime_enable(&pdev->dev); + ret = pm_runtime_get_sync(&pdev->dev); + if (ret < 0) { + pm_runtime_put_noidle(&pdev->dev); + goto iounmap_base; + } + /* Determine number of locks */ i = readl(io_base + SYSSTATUS_OFFSET); i >>= SPINLOCK_NUMLOCKS_BIT_OFFSET; + /* + * runtime PM will make sure the clock of this module is + * enabled again iff at least one lock is requested + */ + ret = pm_runtime_put_sync(&pdev->dev); + if (ret < 0) + goto iounmap_base; + /* one of the four lsb's must be set, and nothing else */ if (hweight_long(i & 0xf) != 1 || i > 8) { ret = -EINVAL; @@ -124,12 +143,6 @@ static int omap_hwspinlock_probe(struct platform_device *pdev) for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++) hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; - /* - * runtime PM will make sure the clock of this module is - * enabled iff at least one lock is requested - */ - pm_runtime_enable(&pdev->dev); - ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops, base_id, num_locks); if (ret) @@ -138,9 +151,9 @@ static int omap_hwspinlock_probe(struct platform_device *pdev) return 0; reg_fail: - pm_runtime_disable(&pdev->dev); kfree(bank); iounmap_base: + pm_runtime_disable(&pdev->dev); iounmap(io_base); return ret; }
The number of hwspinlocks are determined based on the value read from the IP block's SYSSTATUS register. However, the module may not be enabled and clocked, and the read may result in a bus error. This particular issue is seen rather easily on AM33XX, since the module wakeup is software controlled, and it is disabled out of reset. Make sure the module is enabled and clocked before reading the SYSSTATUS register. Signed-off-by: Suman Anna <s-anna@ti.com> --- drivers/hwspinlock/omap_hwspinlock.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-)