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authorAndrzej Hajda <a.hajda@samsung.com>2018-01-15 20:33:57 +0300
committerAndrzej Hajda <a.hajda@samsung.com>2018-06-13 17:27:32 +0300
commit8e627a1b1ce8feb3e1da4428b71b9b4905f04888 (patch)
treebf6413f0d92648a1718bea91eae0a9f609074f97 /drivers/gpu
parent8efaac07d7e6694f39521f9fb8a5c848b712ecee (diff)
downloadlinux-8e627a1b1ce8feb3e1da4428b71b9b4905f04888.tar.xz
drm/bridge/sii8620: fix loops in EDID fetch logic
Function should constantly check if cable is connected and finish in finite time. Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Maciej Purski <m.purski@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180115173357.31067-4-a.hajda@samsung.com
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/bridge/sil-sii8620.c31
1 files changed, 20 insertions, 11 deletions
diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c
index d1e780fba4b6..720bc7c325e0 100644
--- a/drivers/gpu/drm/bridge/sil-sii8620.c
+++ b/drivers/gpu/drm/bridge/sil-sii8620.c
@@ -807,6 +807,7 @@ static void sii8620_burst_rx_all(struct sii8620 *ctx)
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;
@@ -856,23 +857,31 @@ static void sii8620_fetch_edid(struct sii8620 *ctx)
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) {