From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9371C43461 for ; Mon, 14 Sep 2020 06:34:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5DB21208DB for ; Mon, 14 Sep 2020 06:34:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="drHuUM0v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726039AbgINGeL (ORCPT ); Mon, 14 Sep 2020 02:34:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726003AbgINGeK (ORCPT ); Mon, 14 Sep 2020 02:34:10 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57786C06174A; Sun, 13 Sep 2020 23:34:10 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id j34so10717107pgi.7; Sun, 13 Sep 2020 23:34:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Bo/N69mx88es3f8XjhmFZcolMz0xbU++iH9HUek+WK0=; b=drHuUM0vP3sdvwtxiPt61juLMR9Fv4pvmKjT826xStrBMv6YAeeIMir7K8viKUSB1t ukLZ2wX1vD7Hp1Bvp+KpWto2kMHYiSlnk/SWc3th+lwuwvOV4GAwcIU9xr0PxHaW8s9E TbHSeFIWsPlz62jpQ9wpD2MUjctSzhwpE7NFJ3OGYRkUDGUfSWEw2wkKuxp5UOTMr2o2 5l8nCNJnMDu0tGptdGYgDii+fF42uIJ55FmYdAQrGyFXELTSQAbKAoCCQvDk9x6rAkdN IIKBAJnzR3/VPCAMuRUac9CwBOiaDkIVPTfItTvAgsT1VdJqaoRMLlAnvvvNc36/8pJo xpCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Bo/N69mx88es3f8XjhmFZcolMz0xbU++iH9HUek+WK0=; b=fgKab7gNXLJZjnPQSAcMe2jKSkMcVL7WhIu+MLGJ/Q9gqTiQ8kSd9Zfr5pn/X4eHQF ZTfStIzL8f0pb2RL9DY2FGUKEURCJK07Unu9f7P51KKgQanQAf41t0NXx6eiL4a8s5H5 tw4pO0e4/7kApsIgo8h3Yp4t7vp147yAdZ4V2WnxBpyiPsJiiKP/bXCjxzoRYLFfrlTL ZkwHcqo+hA7HKlk9zP5qynDBf7fjaZBcDLeSRFisnxYlDUXKqKTMRUbiwkE37ZsvlPX7 u4NLAcBqbpwmoueoJAWkTSU3ohAueO3KmSXg0aOfvDuuFp5oGy5m5VBD5u9SaSDc+KYS rnTA== X-Gm-Message-State: AOAM530EP/m1Ntv3CkloNPy6yUcy1FW5CAgUB84OzAkAJtAXg06k2gOq Wh99n8eqi7KjziJe11sD/h/63VDzVS0= X-Google-Smtp-Source: ABdhPJx5RBrbXcK8UYuicsYOsD0ncmgqxQf0hfksZjdHwx3Oy09/Hq7yxd7dlZTDQAGEmHxsowiMVA== X-Received: by 2002:a63:d706:: with SMTP id d6mr9566322pgg.318.1600065249705; Sun, 13 Sep 2020 23:34:09 -0700 (PDT) Received: from dtor-ws ([2620:15c:202:201:a6ae:11ff:fe11:fcc3]) by smtp.gmail.com with ESMTPSA id i20sm7489569pgk.77.2020.09.13.23.34.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 13 Sep 2020 23:34:09 -0700 (PDT) Date: Sun, 13 Sep 2020 23:34:07 -0700 From: Dmitry Torokhov To: Furquan Shaikh Cc: Dan Carpenter , linux-input@vger.kernel.org, Linux Kernel Mailing List , Aaron Durbin Subject: Re: [PATCH v2] drivers: input: Use single i2c_transfer transaction when using RM_CMD_BANK_SWITCH Message-ID: <20200914063407.GP1665100@dtor-ws> References: <20200820224551.GX1665100@dtor-ws> <20200821024006.3399663-1-furquan@google.com> <20200909004424.GD1665100@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On Sun, Sep 13, 2020 at 11:04:48PM -0700, Furquan Shaikh wrote: > Hi Dmitry, > > On Tue, Sep 8, 2020 at 5:44 PM Dmitry Torokhov > wrote: > > > > Hi Furquan, > > > > On Thu, Aug 20, 2020 at 07:40:06PM -0700, Furquan Shaikh wrote: > > > On an AMD chromebook, where the same I2C bus is shared by both Raydium > > > touchscreen and a trackpad device, it is observed that interleaving of > > > I2C messages when `raydium_i2c_read_message()` is called leads to the > > > Raydium touch IC reporting incorrect information. This is the sequence > > > that was observed to result in the above issue: > > > > > > * I2C write to Raydium device for RM_CMD_BANK_SWITCH > > > * I2C write to trackpad device > > > * I2C read from trackpad device > > > * I2C write to Raydium device for setting address > > > * I2C read from Raydium device >>>> This provides incorrect > > > information > > > > > > This change adds a new helper function `raydium_i2c_xfer()` that > > > performs I2C transactions to the Raydium device. It uses the register > > > address to decide if RM_CMD_BANK_SWITCH header needs to be sent to the > > > device (i.e. if register address is greater than 255, then bank switch > > > header is sent before the rest of the transaction). Additionally, it > > > ensures that all the I2C operations performed as part of > > > `raydium_i2c_xfer()` are done as a single i2c_transfer. This > > > guarantees that no other transactions are initiated to any other > > > device on the same bus in between. Additionally, > > > `raydium_i2c_{send|read}*` functions are refactored to use this new > > > helper function. > > > > > > Verified with the patch across multiple reboots (>100) that the > > > information reported by the Raydium touchscreen device during probe > > > is correct. > > > > > > Signed-off-by: Furquan Shaikh > > > > > > --- > > > v2: Added a new helper function raydium_i2c_xfer so that all read and > > > send transfers are handled using the same path. This helper function > > > uses register address > 255 to decide whether to send > > > RM_CMD_BANK_SWITCH command. Additionally, __packed keyword is moved > > > to be placed after the structure defintion. > > > > > > drivers/input/touchscreen/raydium_i2c_ts.c | 132 +++++++++------------ > > > 1 file changed, 58 insertions(+), 74 deletions(-) > > > > > > diff --git a/drivers/input/touchscreen/raydium_i2c_ts.c b/drivers/input/touchscreen/raydium_i2c_ts.c > > > index fe245439adee..261e4a290836 100644 > > > --- a/drivers/input/touchscreen/raydium_i2c_ts.c > > > +++ b/drivers/input/touchscreen/raydium_i2c_ts.c > > > @@ -51,6 +51,7 @@ > > > > > > /* Touch relative info */ > > > #define RM_MAX_RETRIES 3 > > > +#define RM_RETRY_DELAY_MS 20 > > > #define RM_MAX_TOUCH_NUM 10 > > > #define RM_BOOT_DELAY_MS 100 > > > > > > @@ -136,114 +137,98 @@ struct raydium_data { > > > bool wake_irq_enabled; > > > }; > > > > > > -static int raydium_i2c_send(struct i2c_client *client, > > > - u8 addr, const void *data, size_t len) > > > +static int raydium_i2c_xfer(struct i2c_client *client, u32 addr, void *data, > > > + size_t len, bool is_read) > > > { > > > - u8 *buf; > > > - int tries = 0; > > > - int ret; > > > - > > > - buf = kmalloc(len + 1, GFP_KERNEL); > > > - if (!buf) > > > - return -ENOMEM; > > > - > > > - buf[0] = addr; > > > - memcpy(buf + 1, data, len); > > > - > > > - do { > > > - ret = i2c_master_send(client, buf, len + 1); > > > - if (likely(ret == len + 1)) > > > - break; > > > - > > > - msleep(20); > > > - } while (++tries < RM_MAX_RETRIES); > > > - > > > - kfree(buf); > > > - > > > - if (unlikely(ret != len + 1)) { > > > - if (ret >= 0) > > > - ret = -EIO; > > > - dev_err(&client->dev, "%s failed: %d\n", __func__, ret); > > > - return ret; > > > - } > > > + struct raydium_bank_switch_header { > > > + u8 cmd; > > > + __be32 be_addr; > > > + } __packed header = { > > > + .cmd = RM_CMD_BANK_SWITCH, > > > + .be_addr = cpu_to_be32(addr), > > > + }; > > > > > > - return 0; > > > -} > > > + u8 reg_addr = addr & 0xff; > > > > > > -static int raydium_i2c_read(struct i2c_client *client, > > > - u8 addr, void *data, size_t len) > > > -{ > > > struct i2c_msg xfer[] = { > > > + { > > > + .addr = client->addr, > > > + .len = sizeof(header), > > > + .buf = (u8 *)&header, > > > + }, > > > { > > > .addr = client->addr, > > > .len = 1, > > > - .buf = &addr, > > > + .buf = ®_addr, > > > }, > > > { > > > .addr = client->addr, > > > - .flags = I2C_M_RD, > > > .len = len, > > > .buf = data, > > > + .flags = is_read ? I2C_M_RD : 0, > > > } > > > }; > > > + > > > + /* > > > + * If address is greater than 255, then RM_CMD_BANK_SWITCH needs to be > > > + * sent first. Else, skip the header i.e. xfer[0]. > > > + */ > > > + int xfer_start_idx = (addr > 0xff) ? 0 : 1; > > > + size_t xfer_count = ARRAY_SIZE(xfer) - xfer_start_idx; > > > int ret; > > > > > > - ret = i2c_transfer(client->adapter, xfer, ARRAY_SIZE(xfer)); > > > - if (unlikely(ret != ARRAY_SIZE(xfer))) > > > - return ret < 0 ? ret : -EIO; > > > + ret = i2c_transfer(client->adapter, &xfer[xfer_start_idx], xfer_count); > > > + if (likely(ret == xfer_count)) > > > + return 0; > > > > > > - return 0; > > > + return -EIO; > > > > We are losing real error here, I'll change this to > > > > return ret < 0 ? ret : -EIO; > > > > > } > > Looks good. > > > > > > > -static int raydium_i2c_read_message(struct i2c_client *client, > > > - u32 addr, void *data, size_t len) > > > +static int raydium_i2c_send(struct i2c_client *client, u32 addr, > > > + const void *data, size_t len) > > > { > > > - __be32 be_addr; > > > + int tries = 0; > > > + int ret; > > > + > > > + do { > > > + ret = raydium_i2c_xfer(client, addr, (void *)data, len, false); > > > + if (likely(ret == 0)) > > > + return 0; > > > + > > > + msleep(RM_RETRY_DELAY_MS); > > > + } while (++tries < RM_MAX_RETRIES); > > > + > > > + dev_err(&client->dev, "%s failed\n", __func__); > > > + return -EIO; > > > > Again losing real error here, I'll rename ret to error and do > > > > return error; > > > > here. > > Looks good. > > > > > > +} > > > + > > > +static int raydium_i2c_read(struct i2c_client *client, u32 addr, void *data, > > > + size_t len) > > > +{ > > > + int ret; > > > size_t xfer_len; > > > - int error; > > > > > > while (len) { > > > xfer_len = min_t(size_t, len, RM_MAX_READ_SIZE); > > > + ret = raydium_i2c_xfer(client, addr, data, len, true); > > > > I think this needs to be xfer_len, not len. > > Good catch. Yes, this needs to be xfer_len. > > > > > I can fix it up locally if you agree. > > The suggestions look good to me. Thank you! Great, applied. -- Dmitry