[{"id":3683327,"web_url":"http://patchwork.ozlabs.org/comment/3683327/","msgid":"<41960ee3-8645-4d79-0a01-e9642b674a6b@nabladev.com>","list_archive_url":null,"date":"2026-04-28T09:55:08","subject":"Re: [PATCH] i2c: imx_lpi2c: Fix MSR status check issue in STOP","submitter":{"id":91409,"url":"http://patchwork.ozlabs.org/api/people/91409/","name":"Heiko Schocher","email":"hs@nabladev.com"},"content":"Hello Ye Li,\n\nOn 28.04.26 10:53, Ye Li wrote:\n> In bus_i2c_stop, the MSR SDF is checked in a loop after stop command\n> is sent. Meanwhile, some error status in MSR is also checked by\n> imx_lpci2c_check_clear_error. But the imx_lpci2c_check_clear_error\n> will clear the MSR.\n> \n> It causes problem in below situation:\n> In current loop, SDF does not set, but error status is found by\n> imx_lpci2c_check_clear_error (for example, NDF), then NDF will be cleared\n> and result has NDF error. However, because SDF does not set in this loop,\n> it goes not next loop. When SDF is set in next loop,\n> imx_lpci2c_check_clear_error is re-executed, but as the MSR is cleared,\n> the result is 0. Then the stop return 0. But it should return NDF error.\n> \n> Signed-off-by: Ye Li \n> ---\n> drivers/i2c/imx_lpi2c.c | 4 +++-\n> 1 file changed, 3 insertions(+), 1 deletion(-)\n> \n> diff --git a/drivers/i2c/imx_lpi2c.c b/drivers/i2c/imx_lpi2c.c\n> index a309fd6f07c..e2b4fd334ec 100644\n> --- a/drivers/i2c/imx_lpi2c.c\n> +++ b/drivers/i2c/imx_lpi2c.c\n> @@ -239,7 +239,6 @@ static int bus_i2c_stop(struct udevice *bus)\n> \tstart_time = get_timer(0);\n> \twhile (1) {\n> \t\tstatus = readl(®s->msr);\n> -\t\tresult = imx_lpci2c_check_clear_error(regs);\n\nWouldn;t it be better to evaluate bits in result too, and return\nif error bits found?\n\n> \t\t/* stop detect flag */\n> \t\tif (status & LPI2C_MSR_SDF_MASK) {\n> \t\t\t/* clear stop flag */\n> @@ -250,10 +249,13 @@ static int bus_i2c_stop(struct udevice *bus)\n> \n> \t\tif (get_timer(start_time) > LPI2C_NACK_TOUT_MS) {\n> \t\t\tdebug(\"stop timeout\\n\");\n> +\t\t\tresult = imx_lpci2c_check_clear_error(regs);\n> \t\t\treturn -ETIMEDOUT;\n> \t\t}\n> \t}\n> \n> +\tresult = imx_lpci2c_check_clear_error(regs);\n> +\n> \treturn result;\n> }\n> \n> \n\nbye,\nHeiko","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=nabladev.com header.i=@nabladev.com header.a=rsa-sha256\n header.s=dkim header.b=N7G64aAG;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.denx.de\n (client-ip=85.214.62.61; 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Linux x86_64; rv:91.0) Gecko/20100101\n Thunderbird/91.2.0","Subject":"Re: [PATCH] i2c: imx_lpi2c: Fix MSR status check issue in STOP","Content-Language":"en-US","To":"Ye Li , festevam@gmail.com, u-boot@lists.denx.de,\n peng.fan@nxp.com","Cc":"uboot-imx@nxp.com","References":"<20260428085312.1808358-1-ye.li@nxp.com>","From":"Heiko Schocher ","In-Reply-To":"<20260428085312.1808358-1-ye.li@nxp.com>","Content-Type":"text/plain; charset=UTF-8; format=flowed","Content-Transfer-Encoding":"8bit","X-Last-TLS-Session-Version":"TLSv1.3","X-BeenThere":"u-boot@lists.denx.de","X-Mailman-Version":"2.1.39","Precedence":"list","List-Id":"U-Boot discussion ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"u-boot-bounces@lists.denx.de","Sender":"\"U-Boot\" ","X-Virus-Scanned":"clamav-milter 0.103.8 at phobos.denx.de","X-Virus-Status":"Clean"}}]