4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrzej Hajda <a.hajda@xxxxxxxxxxx> [ Upstream commit 8e627a1b1ce8feb3e1da4428b71b9b4905f04888 ] Function should constantly check if cable is connected and finish in finite time. Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Reviewed-by: Maciej Purski <m.purski@xxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20180115173357.31067-4-a.hajda@xxxxxxxxxxx Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/bridge/sil-sii8620.c | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) --- a/drivers/gpu/drm/bridge/sil-sii8620.c +++ b/drivers/gpu/drm/bridge/sil-sii8620.c @@ -788,6 +788,7 @@ static void sii8620_burst_rx_all(struct static void sii8620_fetch_edid(struct sii8620 *ctx) { u8 lm_ddc, ddc_cmd, int3, cbus; + unsigned long timeout; int fetched, i; int edid_len = EDID_LENGTH; u8 *edid; @@ -837,23 +838,31 @@ static void sii8620_fetch_edid(struct si REG_DDC_CMD, ddc_cmd | VAL_DDC_CMD_ENH_DDC_READ_NO_ACK ); - do { - int3 = sii8620_readb(ctx, REG_INTR3); + int3 = 0; + timeout = jiffies + msecs_to_jiffies(200); + for (;;) { cbus = sii8620_readb(ctx, REG_CBUS_STATUS); - - if (int3 & BIT_DDC_CMD_DONE) - break; - - if (!(cbus & BIT_CBUS_STATUS_CBUS_CONNECTED)) { + if (~cbus & BIT_CBUS_STATUS_CBUS_CONNECTED) { + kfree(edid); + edid = NULL; + goto end; + } + if (int3 & BIT_DDC_CMD_DONE) { + if (sii8620_readb(ctx, REG_DDC_DOUT_CNT) + >= FETCH_SIZE) + break; + } else { + int3 = sii8620_readb(ctx, REG_INTR3); + } + if (time_is_before_jiffies(timeout)) { + ctx->error = -ETIMEDOUT; + dev_err(ctx->dev, "timeout during EDID read\n"); kfree(edid); edid = NULL; goto end; } - } while (1); - - sii8620_readb(ctx, REG_DDC_STATUS); - while (sii8620_readb(ctx, REG_DDC_DOUT_CNT) < FETCH_SIZE) usleep_range(10, 20); + } sii8620_read_buf(ctx, REG_DDC_DATA, edid + fetched, FETCH_SIZE); if (fetched + FETCH_SIZE == EDID_LENGTH) {
