From patchwork Tue May 14 17:20:55 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Anderson X-Patchwork-Id: 13664294 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A61FFC04FFE for ; Tue, 14 May 2024 17:22:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AE7A910E564; Tue, 14 May 2024 17:22:10 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.b="NklVaexs"; dkim-atps=neutral Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) by gabe.freedesktop.org (Postfix) with ESMTPS id 779A110E564 for ; Tue, 14 May 2024 17:22:05 +0000 (UTC) Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-1eeabda8590so42448435ad.0 for ; Tue, 14 May 2024 10:22:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1715707324; x=1716312124; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=eWXom50XipzNjzHaZ1zsjgGu8Jncm2WyeMrvUg1K2SY=; b=NklVaexsmu7bUleKY+fWjfNGWOwUdy+Ss6FWrZfsH4ncFQTE9g8cMtMdC5eNVGqW78 NsrJeli7P/FzdgaTUeSsQ+UYenDy51Sl4Ey2rgqL3y8ox6tPu8N6BAfp/A1EaTMwFHPy ZClyY9Q+bnU+4xe0YZdYnhuZyXIl1UZCRsfqM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1715707324; x=1716312124; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=eWXom50XipzNjzHaZ1zsjgGu8Jncm2WyeMrvUg1K2SY=; b=HT7cdq04WFfSsm4+OHhDUwqRoYW4k+pO8jjQRzxQQC1UFoerJGB+X/xc7DDS5XtJC9 PvdoGlLYfxJOtjPe22Ci4IJICgDUakH8mtoC7HmOrgu30C+QVzYGFaoOQDoKDsdS+/ht gSkPOVLUBQ/smuMU8+ZUm4lqkL+iQAabCEQpNz5vqWifH48hpIuHjC8BAoSheBuFO/0L MKeftgTDuBRGz7HORYj2QVqdde3MovlSfaOD7o8gVwa8M9S5khQvQBBjjxf9EM6/wXSb pEHGwtzDpdd8xfDMy68SusINY+ekGChs0UA2Fz1kArzurC1KPGBQBBvmFN45b2ZbpKmb jUkA== X-Gm-Message-State: AOJu0Yx6vXD4YTIAtWitIAsevQmGIQMzfEb6f35yPD7poNuHyzOcrKvY a8glI96xIbw0og/KsfNLdUE32VT3xtYGoyIgihni80cJGyNG1NQ+12nWk6lpmOlQW5Gb4uUfn1Q = X-Google-Smtp-Source: AGHT+IET164Vn8HsNwakp0lGVkBLImU0h60UvQ3603v+iu9xukqAzgvZgNQlAq5pxAQJWIowtmRX7w== X-Received: by 2002:a17:902:d58e:b0:1e2:65b3:de68 with SMTP id d9443c01a7336-1ef43e28388mr169829265ad.19.1715707323799; Tue, 14 May 2024 10:22:03 -0700 (PDT) Received: from dianders.sjc.corp.google.com ([2620:15c:9d:2:ef10:6fdf:5041:421f]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1ef0bf3101csm100147575ad.121.2024.05.14.10.22.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 May 2024 10:22:03 -0700 (PDT) From: Douglas Anderson To: dri-devel@lists.freedesktop.org Cc: Javier Martinez Canillas , lvzhaoxiong@huaqin.corp-partner.google.com, Jani Nikula , Neil Armstrong , Brian Norris , Sam Ravnborg , Dmitry Baryshkov , Maxime Ripard , Joel Selvaraj , Hsin-Yi Wang , Cong Yang , Linus Walleij , Douglas Anderson , Daniel Vetter , David Airlie , Jonathan Corbet , Maarten Lankhorst , Thomas Zimmermann , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 5/9] drm/mipi-dsi: Introduce mipi_dsi_*_write_seq_multi() Date: Tue, 14 May 2024 10:20:55 -0700 Message-ID: <20240514102056.v5.5.Ie94246c30fe95101e0e26dd5f96e976dbeb8f242@changeid> X-Mailer: git-send-email 2.45.0.rc1.225.g2a3ae87e7f-goog In-Reply-To: <20240514172136.1578498-1-dianders@chromium.org> References: <20240514172136.1578498-1-dianders@chromium.org> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The current mipi_dsi_*_write_seq() macros are non-intutitive because they contain a hidden "return" statement that will return out of the _caller_ of the macro. Let's mark them as deprecated and instead introduce some new macros that are more intuitive. These new macros are less optimal when an error occurs but should behave more optimally when there is no error. Specifically these new macros cause smaller code to get generated and the code size savings (less to fetch from RAM, less cache space used, less RAM used) are important. Since the error case isn't something we need to optimize for and these new macros are easier to understand and more flexible, they should be used. After converting to use these new functions, one example shows some nice savings while also being easier to understand. $ scripts/bloat-o-meter \ ...after/panel-novatek-nt36672e.ko \ ...ctx/panel-novatek-nt36672e.ko add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-988 (-988) Function old new delta nt36672e_1080x2408_60hz_init 6236 5248 -988 Total: Before=10651, After=9663, chg -9.28% Reviewed-by: Neil Armstrong Reviewed-by: Linus Walleij Signed-off-by: Douglas Anderson --- Right now this patch introduces two new functions in drm_mipi_dsi.c. Alternatively we could have changed the prototype of the "chatty" functions and made the deprecated macros adapt to the new prototype. While this sounds nice, it bloated callers of the deprecated functioin a bit because it caused the compiler to emit less optimal code. It doesn't seem terrible to add two more functions, so I went that way. There may be cases where callers who aren't writing many sequences prefer to use the "chatty" versions anyway. (no changes since v3) Changes in v3: - Add a TODO item for cleaning up the deprecated macros/functions. - Inline kerneldoc comments for struct mipi_dsi_multi_context. Changes in v2: - New Documentation/gpu/todo.rst | 18 ++++++++++ drivers/gpu/drm/drm_mipi_dsi.c | 56 ++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 62 ++++++++++++++++++++++++++++++++++ 3 files changed, 136 insertions(+) diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index e2a0585915b3..2734b8a34541 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -494,6 +494,24 @@ Contact: Douglas Anderson Level: Starter/Intermediate +Transition away from using mipi_dsi_*_write_seq() +------------------------------------------------- + +The macros mipi_dsi_generic_write_seq() and mipi_dsi_dcs_write_seq() are +non-intuitive because, if there are errors, they return out of the *caller's* +function. We should move all callers to use mipi_dsi_generic_write_seq_multi() +and mipi_dsi_dcs_write_seq_multi() macros instead. + +Once all callers are transitioned, the macros and the functions that they call, +mipi_dsi_generic_write_chatty() and mipi_dsi_dcs_write_buffer_chatty(), can +probably be removed. Alternatively, if people feel like the _multi() variants +are overkill for some use cases, we could keep the mipi_dsi_*_write_seq() +variants but change them not to return out of the caller. + +Contact: Douglas Anderson + +Level: Starter + Core refactorings ================= diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 4d2685d5a6e0..26c7383406c1 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -792,6 +792,34 @@ int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_generic_write_chatty); +/** + * mipi_dsi_generic_write_multi() - mipi_dsi_generic_write_chatty() w/ accum_err + * @ctx: Context for multiple DSI transactions + * @payload: buffer containing the payload + * @size: size of payload buffer + * + * Like mipi_dsi_generic_write_chatty() but deals with errors in a way that + * makes it convenient to make several calls in a row. + */ +void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx, + const void *payload, size_t size) +{ + struct mipi_dsi_device *dsi = ctx->dsi; + struct device *dev = &dsi->dev; + ssize_t ret; + + if (ctx->accum_err) + return; + + ret = mipi_dsi_generic_write(dsi, payload, size); + if (ret < 0) { + ctx->accum_err = ret; + dev_err(dev, "sending generic data %*ph failed: %d\n", + (int)size, payload, ctx->accum_err); + } +} +EXPORT_SYMBOL(mipi_dsi_generic_write_multi); + /** * mipi_dsi_generic_read() - receive data using a generic read packet * @dsi: DSI peripheral device @@ -908,6 +936,34 @@ int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer_chatty); +/** + * mipi_dsi_dcs_write_buffer_multi - mipi_dsi_dcs_write_buffer_chatty() w/ accum_err + * @ctx: Context for multiple DSI transactions + * @data: buffer containing data to be transmitted + * @len: size of transmission buffer + * + * Like mipi_dsi_dcs_write_buffer_chatty() but deals with errors in a way that + * makes it convenient to make several calls in a row. + */ +void mipi_dsi_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx, + const void *data, size_t len) +{ + struct mipi_dsi_device *dsi = ctx->dsi; + struct device *dev = &dsi->dev; + ssize_t ret; + + if (ctx->accum_err) + return; + + ret = mipi_dsi_dcs_write_buffer(dsi, data, len); + if (ret < 0) { + ctx->accum_err = ret; + dev_err(dev, "sending dcs data %*ph failed: %d\n", + (int)len, data, ctx->accum_err); + } +} +EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer_multi); + /** * mipi_dsi_dcs_write() - send DCS write command * @dsi: DSI peripheral device diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 6d68d9927f46..5e9cad541bd6 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -197,6 +197,27 @@ struct mipi_dsi_device { struct drm_dsc_config *dsc; }; +/** + * struct mipi_dsi_multi_context - Context to call multiple MIPI DSI funcs in a row + */ +struct mipi_dsi_multi_context { + /** + * @dsi: Pointer to the MIPI DSI device + */ + struct mipi_dsi_device *dsi; + + /** + * @accum_err: Storage for the accumulated error over the multiple calls + * + * Init to 0. If a function encounters an error then the error code + * will be stored here. If you call a function and this points to a + * non-zero value then the function will be a noop. This allows calling + * a function many times in a row and just checking the error at the + * end to see if any of them failed. + */ + int accum_err; +}; + #define MIPI_DSI_MODULE_PREFIX "mipi-dsi:" #define to_mipi_dsi_device(__dev) container_of_const(__dev, struct mipi_dsi_device, dev) @@ -258,6 +279,8 @@ ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload, size_t size); int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi, const void *payload, size_t size); +void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx, + const void *payload, size_t size); ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params, size_t num_params, void *data, size_t size); @@ -283,6 +306,8 @@ ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi, const void *data, size_t len); int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi, const void *data, size_t len); +void mipi_dsi_dcs_write_buffer_multi(struct mipi_dsi_multi_context *ctx, + const void *data, size_t len); ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd, const void *data, size_t len); ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data, @@ -319,6 +344,9 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, * This macro will print errors for you and will RETURN FROM THE CALLING * FUNCTION (yes this is non-intuitive) upon error. * + * Because of the non-intuitive return behavior, THIS MACRO IS DEPRECATED. + * Please replace calls of it with mipi_dsi_generic_write_seq_multi(). + * * @dsi: DSI peripheral device * @seq: buffer containing the payload */ @@ -331,12 +359,30 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, return ret; \ } while (0) +/** + * mipi_dsi_generic_write_seq_multi - transmit data using a generic write packet + * + * This macro will print errors for you and error handling is optimized for + * callers that call this multiple times in a row. + * + * @ctx: Context for multiple DSI transactions + * @seq: buffer containing the payload + */ +#define mipi_dsi_generic_write_seq_multi(ctx, seq...) \ + do { \ + static const u8 d[] = { seq }; \ + mipi_dsi_generic_write_multi(ctx, d, ARRAY_SIZE(d)); \ + } while (0) + /** * mipi_dsi_dcs_write_seq - transmit a DCS command with payload * * This macro will print errors for you and will RETURN FROM THE CALLING * FUNCTION (yes this is non-intuitive) upon error. * + * Because of the non-intuitive return behavior, THIS MACRO IS DEPRECATED. + * Please replace calls of it with mipi_dsi_dcs_write_seq_multi(). + * * @dsi: DSI peripheral device * @cmd: Command * @seq: buffer containing data to be transmitted @@ -350,6 +396,22 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, return ret; \ } while (0) +/** + * mipi_dsi_dcs_write_seq_multi - transmit a DCS command with payload + * + * This macro will print errors for you and error handling is optimized for + * callers that call this multiple times in a row. + * + * @ctx: Context for multiple DSI transactions + * @cmd: Command + * @seq: buffer containing data to be transmitted + */ +#define mipi_dsi_dcs_write_seq_multi(ctx, cmd, seq...) \ + do { \ + static const u8 d[] = { cmd, seq }; \ + mipi_dsi_dcs_write_buffer_multi(ctx, d, ARRAY_SIZE(d)); \ + } while (0) + /** * struct mipi_dsi_driver - DSI driver * @driver: device driver model driver