From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sifan Naeem Subject: [PATCH v3 2/7] i2c: img-scb: do dummy writes before fifo access Date: Thu, 10 Sep 2015 15:50:02 +0100 Message-ID: <1441896607-16310-3-git-send-email-sifan.naeem@imgtec.com> References: <1441896607-16310-1-git-send-email-sifan.naeem@imgtec.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1441896607-16310-1-git-send-email-sifan.naeem-1AXoQHu6uovQT0dZR+AlfA@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfram Sang , James Hogan , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ezequiel Garcia Cc: Ionela Voinescu , Sifan Naeem List-Id: linux-i2c@vger.kernel.org Move scb_wr_rd_fence to before reading from fifo and writing to fifo to make sure the the first read/write is done after the required number of cycles. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem Acked-by: James Hogan Reviewed-by: James Hartley --- drivers/i2c/busses/i2c-img-scb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-img-scb.c b/drivers/i2c/busses/i2c-img-scb.c index 5c3c61586d4a..0368d91b6805 100644 --- a/drivers/i2c/busses/i2c-img-scb.c +++ b/drivers/i2c/busses/i2c-img-scb.c @@ -534,6 +534,7 @@ static void img_i2c_read_fifo(struct img_i2c *i2c) u32 fifo_status; u8 data; + img_i2c_wr_rd_fence(i2c); fifo_status = img_i2c_readl(i2c, SCB_FIFO_STATUS_REG); if (fifo_status & FIFO_READ_EMPTY) break; @@ -542,7 +543,6 @@ static void img_i2c_read_fifo(struct img_i2c *i2c) *i2c->msg.buf = data; img_i2c_writel(i2c, SCB_READ_FIFO_REG, 0xff); - img_i2c_wr_rd_fence(i2c); i2c->msg.len--; i2c->msg.buf++; } @@ -554,12 +554,12 @@ static void img_i2c_write_fifo(struct img_i2c *i2c) while (i2c->msg.len) { u32 fifo_status; + img_i2c_wr_rd_fence(i2c); fifo_status = img_i2c_readl(i2c, SCB_FIFO_STATUS_REG); if (fifo_status & FIFO_WRITE_FULL) break; img_i2c_writel(i2c, SCB_WRITE_DATA_REG, *i2c->msg.buf); - img_i2c_wr_rd_fence(i2c); i2c->msg.len--; i2c->msg.buf++; } -- 1.7.9.5