From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sifan Naeem Subject: [PATCH 2/8] i2c: img-scb: do dummy writes before fifo access Date: Mon, 27 Jul 2015 12:47:15 +0100 Message-ID: <1437997641-32575-3-git-send-email-sifan.naeem@imgtec.com> References: <1437997641-32575-1-git-send-email-sifan.naeem@imgtec.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1437997641-32575-1-git-send-email-sifan.naeem@imgtec.com> Sender: stable-owner@vger.kernel.org To: Wolfram Sang , James Hogan , linux-i2c@vger.kernel.org Cc: Sifan Naeem , "Stable kernel (v3.19+)" 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: 27bce4 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem Acked-by: James Hogan Cc: Stable kernel (v3.19+) --- 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 5c3c615..0368d91 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