From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@ti.com (Kevin Hilman) Date: Tue, 26 Jun 2012 20:43:32 -0500 Subject: [PATCH 07/11] I2C: OMAP: Handle error check for pm runtime In-Reply-To: <1338288983-15026-8-git-send-email-shubhrajyoti@ti.com> (Shubhrajyoti D.'s message of "Tue, 29 May 2012 16:26:19 +0530") References: <1338288983-15026-1-git-send-email-shubhrajyoti@ti.com> <1338288983-15026-8-git-send-email-shubhrajyoti@ti.com> Message-ID: <874npxv8aj.fsf@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Shubhrajyoti D writes: > If PM runtime get_sync fails return with the error > so that no further reads/writes goes through the interface. > This will avoid possible abort. Add a error message in case > of failure with the cause of the failure. > > Reviewed-by: Kevin Hilman > Signed-off-by: Shubhrajyoti D This patch introduced a regression where the runtime PM usecount will never reach zero and so CORE retention is prevented after any xfer failures... > --- > -v10 Use IS_ERR_VALUE > -v9 Fix the error handling > > drivers/i2c/busses/i2c-omap.c | 14 +++++++++++--- > 1 files changed, 11 insertions(+), 3 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index 44e8cfa..c39b72f 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -585,7 +585,9 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) > int i; > int r; > > - pm_runtime_get_sync(dev->dev); > + r = pm_runtime_get_sync(dev->dev);< > + if (IS_ERR_VALUE(r)) > + return r; This return should be 'goto out' so the runtime PM usecount is decremented by the 'put'. Otherwise, after failure, the usecount remains non-zero, so the device is considered 'active' and keeps the containing power domain active. I found this on a 3730/OveroSTORM where the suspend/resume of MMC fails because I2C is already suspended. After the suspend though, the CORE powerdomain never again hits retention, and I tracked it down to this. I'll send a separate patch to fix this shortly. Kevin