From patchwork Sat Feb 22 13:38:34 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sven Peter via B4 Relay X-Patchwork-Id: 867572 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB63B13AD38; Sat, 22 Feb 2025 13:38:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740231523; cv=none; b=LZYQKmriYQzuQtZDpVbPcHbL7v0+bEXObuG4wbSFOuyaJwpejdzT6Xs7Wa9pCJhfIfAnaLWKPMpGExT59x8a21o/sL7s31rdvK3gCP/mipN1cOGSESeJQVee3dW1BeuIdC3c7bidshwMFhGxOARll46njzTK4QjWJmQzvDuI5iE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740231523; c=relaxed/simple; bh=stV9tpnov4yN5EBBC898RB20QY2wQygLqqMwvyDN5Eo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=PXHlBMfftRADmbmsyriQDEqqTlTkdwXJOkrBHdlH/eSP56+un4mReRY9KetHV4hDIEadK7jOUH1UkjWYri6Fce/qeb81VQTKro142VNUlkwJgVBhQJx7XfksDJPB9coaj0MK82RpPaDcNiMa6hscMuw5DpuJ8+F+KZWroHfGJr4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B0yifpRA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="B0yifpRA" Received: by smtp.kernel.org (Postfix) with ESMTPS id 63EAAC4CEE8; Sat, 22 Feb 2025 13:38:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740231522; bh=stV9tpnov4yN5EBBC898RB20QY2wQygLqqMwvyDN5Eo=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=B0yifpRAfaIfxTZ/0+9c3+UJ6qN5Dz2MYeH33+yGul4+clHOoYOKj7b62QejMT/8g S2CYW0YgBcPqT15Iel2fnamnYJtolkQujb5QiIQsPTkZdjqLWXT7CU4ksITzjNvJme 3d4WC6R1R5DAgSMl2jSpFMrFEJJBtx0cnCv/iiaAk1XbvL4U+/1lDEIgAQ3UBcvPw3 njE1qDOjvXAQliL9xTzqGJZOjKRdSCHxoWzDjLva1JB9wYfEweoMyEP4bsx9JsX2qP d6ZJpK0fstVTAsVJaPQsaRyx+bQOaO0r7zTn6AnlWTFK8XsWNWrUJuxSIBDSlNgPIs 12puhG4AUFbeg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50EF4C021B5; Sat, 22 Feb 2025 13:38:42 +0000 (UTC) From: Sven Peter via B4 Relay Date: Sat, 22 Feb 2025 13:38:34 +0000 Subject: [PATCH 2/4] i2c: pasemi: Improve error recovery Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250222-pasemi-fixes-v1-2-d7ea33d50c5e@svenpeter.dev> References: <20250222-pasemi-fixes-v1-0-d7ea33d50c5e@svenpeter.dev> In-Reply-To: <20250222-pasemi-fixes-v1-0-d7ea33d50c5e@svenpeter.dev> To: Janne Grunau , Alyssa Rosenzweig , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Andi Shyti Cc: linuxppc-dev@lists.ozlabs.org, asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Sven Peter , Hector Martin X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4391; i=sven@svenpeter.dev; h=from:subject:message-id; bh=FOQIV4q7QbwGt8D9/MCWC8cZNMpith++DiclVxlmaig=; b=owGbwMvMwCHmIlirolUq95LxtFoSQ/rOyzHXHGYEMRdvvZQdf+b35HAG7jV1fXEBv+3epzBOj Pfwu3K+o5SFQYyDQVZMkWX7fnvTJw/fCC7ddOk9zBxWJpAhDFycAjCRhpmMDGfYv3fz+dwVN3j+ 47OXaKGTUe2hyf/CpdvNZfxfSR8pY2Rk6BTTbD4r61F6tmjvwZU3dq5/MKWRSXnxd41XE9lvpYp PZwYA X-Developer-Key: i=sven@svenpeter.dev; a=openpgp; fpr=A1E3E34A2B3C820DBC4955E5993B08092F131F93 X-Endpoint-Received: by B4 Relay for sven@svenpeter.dev/default with auth_id=167 X-Original-From: Sven Peter Reply-To: sven@svenpeter.dev From: Hector Martin The hardware (supposedly) has a 25ms timeout for clock stretching and the driver uses 100ms which should be plenty. The error reocvery itself is however lacking. Add handling for all the missing error condition, and better recovery in pasemi_smb_clear(). Also move the timeout to a #define since it's used in multiple places now. Signed-off-by: Hector Martin [sven: adjusted commit message after splitting the commit into two] Signed-off-by: Sven Peter --- drivers/i2c/busses/i2c-pasemi-core.c | 70 +++++++++++++++++++++++++++++------- 1 file changed, 58 insertions(+), 12 deletions(-) diff --git a/drivers/i2c/busses/i2c-pasemi-core.c b/drivers/i2c/busses/i2c-pasemi-core.c index bd128ab2e2eb..770b86b92a10 100644 --- a/drivers/i2c/busses/i2c-pasemi-core.c +++ b/drivers/i2c/busses/i2c-pasemi-core.c @@ -52,6 +52,8 @@ #define CTL_UJM BIT(8) #define CTL_CLK_M GENMASK(7, 0) +#define TRANSFER_TIMEOUT_MS 100 + static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val) { dev_dbg(smbus->dev, "smbus write reg %x val %08x\n", reg, val); @@ -80,23 +82,45 @@ static void pasemi_reset(struct pasemi_smbus *smbus) reinit_completion(&smbus->irq_completion); } -static void pasemi_smb_clear(struct pasemi_smbus *smbus) +static int pasemi_smb_clear(struct pasemi_smbus *smbus) { unsigned int status; + int timeout = TRANSFER_TIMEOUT_MS; status = reg_read(smbus, REG_SMSTA); + + /* First wait for the bus to go idle */ + while ((status & (SMSTA_XIP | SMSTA_JAM)) && timeout--) { + msleep(1); + status = reg_read(smbus, REG_SMSTA); + } + + if (timeout < 0) { + dev_warn(smbus->dev, "Bus is still stuck (status 0x%08x)\n", status); + return -EIO; + } + + /* If any badness happened or there is data in the FIFOs, reset the FIFOs */ + if ((status & (SMSTA_MRNE | SMSTA_JMD | SMSTA_MTO | SMSTA_TOM | SMSTA_MTN | SMSTA_MTA)) || + !(status & SMSTA_MTE)) + pasemi_reset(smbus); + + /* Clear the flags */ reg_write(smbus, REG_SMSTA, status); + + return 0; } static int pasemi_smb_waitready(struct pasemi_smbus *smbus) { - int timeout = 100; + int timeout = TRANSFER_TIMEOUT_MS; unsigned int status; if (smbus->use_irq) { reinit_completion(&smbus->irq_completion); - reg_write(smbus, REG_IMASK, SMSTA_XEN | SMSTA_MTN); - wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(100)); + /* XEN should be set when a transaction terminates, whether due to error or not */ + reg_write(smbus, REG_IMASK, SMSTA_XEN); + wait_for_completion_timeout(&smbus->irq_completion, msecs_to_jiffies(timeout)); reg_write(smbus, REG_IMASK, 0); status = reg_read(smbus, REG_SMSTA); } else { @@ -107,16 +131,36 @@ static int pasemi_smb_waitready(struct pasemi_smbus *smbus) } } - /* Got NACK? */ - if (status & SMSTA_MTN) - return -ENXIO; + /* Controller timeout? */ + if (status & SMSTA_TOM) { + dev_warn(smbus->dev, "Controller timeout, status 0x%08x\n", status); + return -EIO; + } - if (timeout < 0) { - dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status); - reg_write(smbus, REG_SMSTA, status); + /* Peripheral timeout? */ + if (status & SMSTA_MTO) { + dev_warn(smbus->dev, "Peripheral timeout, status 0x%08x\n", status); return -ETIME; } + /* Still stuck in a transaction? */ + if (status & SMSTA_XIP) { + dev_warn(smbus->dev, "Bus stuck, status 0x%08x\n", status); + return -EIO; + } + + /* Arbitration loss? */ + if (status & SMSTA_MTA) { + dev_warn(smbus->dev, "Arbitration loss, status 0x%08x\n", status); + return -EBUSY; + } + + /* Got NACK? */ + if (status & SMSTA_MTN) { + dev_warn(smbus->dev, "NACK, status 0x%08x\n", status); + return -ENXIO; + } + /* Clear XEN */ reg_write(smbus, REG_SMSTA, SMSTA_XEN); @@ -177,7 +221,8 @@ static int pasemi_i2c_xfer(struct i2c_adapter *adapter, struct pasemi_smbus *smbus = adapter->algo_data; int ret, i; - pasemi_smb_clear(smbus); + if (pasemi_smb_clear(smbus)) + return -EIO; ret = 0; @@ -200,7 +245,8 @@ static int pasemi_smb_xfer(struct i2c_adapter *adapter, addr <<= 1; read_flag = read_write == I2C_SMBUS_READ; - pasemi_smb_clear(smbus); + if (pasemi_smb_clear(smbus)) + return -EIO; switch (size) { case I2C_SMBUS_QUICK: