Through a cooperative effort between Hsin-Yi Wang and Dmitry Baryshkov, we have realized the dev_err() in the mipi_dsi_*_write_seq() macros was causing quite a bit of bloat to the kernel. Let's hoist this call into drm_mipi_dsi.c by adding a "chatty" version of the functions that includes the print. While doing this, add a bit more comments to these macros making it clear that they print errors and also that they return out of _the caller's_ function. Without any changes to clients this gives a nice savings. Building with my build system shows one example: $ scripts/bloat-o-meter \ .../before/panel-novatek-nt36672e.ko \ .../after/panel-novatek-nt36672e.ko add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-4404 (-4404) Function old new delta nt36672e_1080x2408_60hz_init 10640 6236 -4404 Total: Before=15055, After=10651, chg -29.25% Note that given the change in location of the print it's harder to include the "cmd" in the printout for mipi_dsi_dcs_write_seq() since, theoretically, someone could call the new chatty function with a zero-size array and it would be illegal to dereference data[0]. There's a printk format to print the whole buffer and this is probably more useful for debugging anyway. Given that we're doing this for mipi_dsi_dcs_write_seq(), let's also print the buffer for mipi_dsi_generic_write_seq() in the error case. It should be noted that the current consensus of DRM folks is that the mipi_dsi_*_write_seq() should be deprecated due to the non-intuitive return behavior. A future patch will formally mark them as deprecated and provide an alternative. Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> --- Changes in v3: - Rebased upon patch to remove ratelimit of prints. Changes in v2: - Add some comments to the macros about printing and returning. - Change the way err value is handled in prep for next patch. - Modify commit message now that this is part of a series. - Rebased upon patches to avoid theoretical int overflow. drivers/gpu/drm/drm_mipi_dsi.c | 56 ++++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 47 +++++++++++++++------------- 2 files changed, 82 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 795001bb7ff1..8593d9ed5891 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -764,6 +764,34 @@ ssize_t mipi_dsi_generic_write(struct mipi_dsi_device *dsi, const void *payload, } EXPORT_SYMBOL(mipi_dsi_generic_write); +/** + * mipi_dsi_generic_write_chatty() - mipi_dsi_generic_write() w/ an error log + * @dsi: DSI peripheral device + * @payload: buffer containing the payload + * @size: size of payload buffer + * + * Like mipi_dsi_generic_write() but includes a dev_err_ratelimited() + * call for you and returns 0 upon success, not the number of bytes sent. + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi, + const void *payload, size_t size) +{ + struct device *dev = &dsi->dev; + ssize_t ret; + + ret = mipi_dsi_generic_write(dsi, payload, size); + if (ret < 0) { + dev_err(dev, "sending generic data %*ph failed: %zd\n", + (int)size, payload, ret); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_generic_write_chatty); + /** * mipi_dsi_generic_read() - receive data using a generic read packet * @dsi: DSI peripheral device @@ -852,6 +880,34 @@ ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer); +/** + * mipi_dsi_dcs_write_buffer_chatty - mipi_dsi_dcs_write_buffer() w/ an error log + * @dsi: DSI peripheral device + * @data: buffer containing data to be transmitted + * @len: size of transmission buffer + * + * Like mipi_dsi_dcs_write_buffer() but includes a dev_err_ratelimited() + * call for you and returns 0 upon success, not the number of bytes sent. + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi, + const void *data, size_t len) +{ + struct device *dev = &dsi->dev; + ssize_t ret; + + ret = mipi_dsi_dcs_write_buffer(dsi, data, len); + if (ret < 0) { + dev_err(dev, "sending dcs data %*ph failed: %zd\n", + (int)len, data, ret); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_dcs_write_buffer_chatty); + /** * 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 67967be48dbd..6d68d9927f46 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -256,6 +256,8 @@ int mipi_dsi_picture_parameter_set(struct mipi_dsi_device *dsi, 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); ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const void *params, size_t num_params, void *data, size_t size); @@ -279,6 +281,8 @@ enum mipi_dsi_dcs_tear_mode { 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); 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, @@ -311,38 +315,39 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, /** * mipi_dsi_generic_write_seq - transmit data using a generic write packet + * + * This macro will print errors for you and will RETURN FROM THE CALLING + * FUNCTION (yes this is non-intuitive) upon error. + * * @dsi: DSI peripheral device * @seq: buffer containing the payload */ -#define mipi_dsi_generic_write_seq(dsi, seq...) \ - do { \ - static const u8 d[] = { seq }; \ - struct device *dev = &dsi->dev; \ - ssize_t ret; \ - ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d)); \ - if (ret < 0) { \ - dev_err(dev, "transmit data failed: %zd\n", ret); \ - return ret; \ - } \ +#define mipi_dsi_generic_write_seq(dsi, seq...) \ + do { \ + static const u8 d[] = { seq }; \ + int ret; \ + ret = mipi_dsi_generic_write_chatty(dsi, d, ARRAY_SIZE(d)); \ + if (ret < 0) \ + return ret; \ } 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. + * * @dsi: DSI peripheral device * @cmd: Command * @seq: buffer containing data to be transmitted */ -#define mipi_dsi_dcs_write_seq(dsi, cmd, seq...) \ - do { \ - static const u8 d[] = { cmd, seq }; \ - struct device *dev = &dsi->dev; \ - ssize_t ret; \ - ret = mipi_dsi_dcs_write_buffer(dsi, d, ARRAY_SIZE(d)); \ - if (ret < 0) { \ - dev_err(dev, "sending command %#02x failed: %zd\n", \ - cmd, ret); \ - return ret; \ - } \ +#define mipi_dsi_dcs_write_seq(dsi, cmd, seq...) \ + do { \ + static const u8 d[] = { cmd, seq }; \ + int ret; \ + ret = mipi_dsi_dcs_write_buffer_chatty(dsi, d, ARRAY_SIZE(d)); \ + if (ret < 0) \ + return ret; \ } while (0) /** -- 2.45.0.rc0.197.gbae5840b3b-goog