From 75c65ee20adebca6ac29d6f9d301ced073dd8030 Mon Sep 17 00:00:00 2001 From: Robert Tarasov Date: Thu, 12 Oct 2017 17:13:50 -0700 Subject: [PATCH] drm/udl: Reading all edid blocks in DRM/UDL driver Now DRM/UDL driver retreives all edid data blocks instead of only base one. Previous approch could lead to improper initialization of video mode with certain monitors. Signed-off-by: Robert Tarasov Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher Link: https://patchwork.freedesktop.org/patch/msgid/20171013001350.172155-2-tutankhamen@chromium.org --- drivers/gpu/drm/udl/udl_connector.c | 106 +++++++++++++++++++++++------------- 1 file changed, 68 insertions(+), 38 deletions(-) diff --git a/drivers/gpu/drm/udl/udl_connector.c b/drivers/gpu/drm/udl/udl_connector.c index b4d1464d2d87..c0bbd1ce15f0 100644 --- a/drivers/gpu/drm/udl/udl_connector.c +++ b/drivers/gpu/drm/udl/udl_connector.c @@ -17,42 +17,79 @@ #include "udl_connector.h" #include "udl_drv.h" -/* dummy connector to just get EDID, - all UDL appear to have a DVI-D */ - -static u8 *udl_get_edid(struct udl_device *udl) +static bool udl_get_edid_block(struct udl_device *udl, int block_idx, + u8 *buff) { - u8 *block; - char *rbuf; int ret, i; + u8 *read_buff; - block = kmalloc(EDID_LENGTH, GFP_KERNEL); - if (block == NULL) - return NULL; - - rbuf = kmalloc(2, GFP_KERNEL); - if (rbuf == NULL) - goto error; + read_buff = kmalloc(2, GFP_KERNEL); + if (!read_buff) + return false; for (i = 0; i < EDID_LENGTH; i++) { + int bval = (i + block_idx * EDID_LENGTH) << 8; ret = usb_control_msg(udl->udev, - usb_rcvctrlpipe(udl->udev, 0), (0x02), - (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2, - HZ); + usb_rcvctrlpipe(udl->udev, 0), + (0x02), (0x80 | (0x02 << 5)), bval, + 0xA1, read_buff, 2, HZ); if (ret < 1) { DRM_ERROR("Read EDID byte %d failed err %x\n", i, ret); - goto error; + kfree(read_buff); + return false; } - block[i] = rbuf[1]; + buff[i] = read_buff[1]; } - kfree(rbuf); - return block; + kfree(read_buff); + return true; +} -error: - kfree(block); - kfree(rbuf); - return NULL; +static bool udl_get_edid(struct udl_device *udl, u8 **result_buff, + int *result_buff_size) +{ + int i, extensions; + u8 *block_buff = NULL, *buff_ptr; + + block_buff = kmalloc(EDID_LENGTH, GFP_KERNEL); + if (block_buff == NULL) + return false; + + if (udl_get_edid_block(udl, 0, block_buff) && + memchr_inv(block_buff, 0, EDID_LENGTH)) { + extensions = ((struct edid *)block_buff)->extensions; + if (extensions > 0) { + /* we have to read all extensions one by one */ + *result_buff_size = EDID_LENGTH * (extensions + 1); + *result_buff = kmalloc(*result_buff_size, GFP_KERNEL); + buff_ptr = *result_buff; + if (buff_ptr == NULL) { + kfree(block_buff); + return false; + } + memcpy(buff_ptr, block_buff, EDID_LENGTH); + kfree(block_buff); + buff_ptr += EDID_LENGTH; + for (i = 1; i < extensions; ++i) { + if (udl_get_edid_block(udl, i, buff_ptr)) { + buff_ptr += EDID_LENGTH; + } else { + kfree(*result_buff); + *result_buff = NULL; + return false; + } + } + return true; + } + /* we have only base edid block */ + *result_buff = block_buff; + *result_buff_size = EDID_LENGTH; + return true; + } + + kfree(block_buff); + + return false; } static int udl_get_modes(struct drm_connector *connector) @@ -84,33 +121,26 @@ static int udl_mode_valid(struct drm_connector *connector, static enum drm_connector_status udl_detect(struct drm_connector *connector, bool force) { - struct edid *edid; + u8 *edid_buff = NULL; + int edid_buff_size = 0; struct udl_device *udl = connector->dev->dev_private; struct udl_drm_connector *udl_connector = container_of(connector, struct udl_drm_connector, connector); + /* cleanup previous edid */ if (udl_connector->edid != NULL) { kfree(udl_connector->edid); udl_connector->edid = NULL; } - edid = (struct edid *)udl_get_edid(udl); - if (!edid || !memchr_inv(edid, 0, EDID_LENGTH)) - return connector_status_disconnected; - udl_connector->edid = edid; - - /* - * We only read the main block, but if the monitor reports extension - * blocks then the drm edid code expects them to be present, so patch - * the extension count to 0. - */ - udl_connector->edid->checksum += - udl_connector->edid->extensions; - udl_connector->edid->extensions = 0; + if (!udl_get_edid(udl, &edid_buff, &edid_buff_size)) + return connector_status_disconnected; + udl_connector->edid = (struct edid *)edid_buff; + return connector_status_connected; } -- 2.11.0