From mboxrd@z Thu Jan 1 00:00:00 1970 From: Addy Ke Subject: [PATCH v4] i2c: rk3x: fix bug that cause transfer fails in master receive mode Date: Sat, 23 Aug 2014 02:00:52 +0800 Message-ID: <1408730452-3552-1-git-send-email-addy.ke@rock-chips.com> References: <1408669991-9703-1-git-send-email-addy.ke@rock-chips.com> Return-path: In-Reply-To: <1408669991-9703-1-git-send-email-addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org, max.schwarz-BGeptl67XyCzQB+pC5nmwQ@public.gmane.org, heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org, olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org, dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org, dmitry.torokhov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org Cc: sergei.shtylyov-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, cf-TNX95d0MmH7DzftRWevZcw@public.gmane.org, xjq-TNX95d0MmH7DzftRWevZcw@public.gmane.org, huangtao-TNX95d0MmH7DzftRWevZcw@public.gmane.org, zyw-TNX95d0MmH7DzftRWevZcw@public.gmane.org, yzq-TNX95d0MmH7DzftRWevZcw@public.gmane.org, hj-TNX95d0MmH7DzftRWevZcw@public.gmane.org, kever.yang-TNX95d0MmH7DzftRWevZcw@public.gmane.org, hl-TNX95d0MmH7DzftRWevZcw@public.gmane.org, caesar.wang-TNX95d0MmH7DzftRWevZcw@public.gmane.org, zhengsq-TNX95d0MmH7DzftRWevZcw@public.gmane.org, Addy Ke List-Id: linux-i2c@vger.kernel.org In rk3x SOC, the I2C controller can receive/transmit up to 32 bytes data in one chunk, so the size of data to be write/read to/from TXDATAx/RXDATAx must be less than or equal 32 bytes at a time. Tested on rk3288-pinky board, elan receive 158 bytes data. Suggested-by: Dmitry Torokhov Signed-off-by: Addy Ke Acked-by: Max Schwarz --- Changes in v2: - Use cleaner syntax as suggested by Sergei. - Update commit message as suggested by Wolfram. Changes in v3: - fix typo: maste --> master and double spaces after 'len' drivers/i2c/busses/i2c-rk3x.c | 4 ++++ Changes in v4: - remove unlikely() annotations, suggested by Dmitry Torokhov diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index b8b2b89..31de730 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -323,6 +323,10 @@ static void rk3x_i2c_handle_read(struct rk3x_i2c *i2c, unsigned int ipd) /* ack interrupt */ i2c_writel(i2c, REG_INT_MBRF, REG_IPD); + /* Can only handle a maximum of 32 bytes at a time */ + if (len > 32) + len = 32; + /* read the data from receive buffer */ for (i = 0; i < len; ++i) { if (i % 4 == 0) -- 1.8.3.2