From: Yunhao Tian t123yh.xyz@gmail.com
stable inclusion from stable-v5.10.137 commit 648d3c87141f2be134754fdcd1c7fb4320bc8300 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
[ Upstream commit 435c249008cba04ed6a7975e9411f3b934620204 ]
In __spi_validate, there's a validation that no partial transfers are accepted (xfer->len % w_size must be zero). When max_chunk is not a multiple of bpw (e.g. max_chunk = 65535, bpw = 16), the transfer will be rejected.
This patch aligns max_chunk to 2 bytes (the maximum value of bpw is 16), so that no partial transfer will occur.
Fixes: d23d4d4dac01 ("drm/tinydrm: Move tinydrm_spi_transfer()")
Signed-off-by: Yunhao Tian t123yh.xyz@gmail.com Signed-off-by: Noralf Trønnes noralf@tronnes.org Link: https://patchwork.freedesktop.org/patch/msgid/20220510030219.2486687-1-t123y... Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- drivers/gpu/drm/drm_mipi_dbi.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c index 230c4fd7131c..9f132229aed1 100644 --- a/drivers/gpu/drm/drm_mipi_dbi.c +++ b/drivers/gpu/drm/drm_mipi_dbi.c @@ -1137,6 +1137,13 @@ int mipi_dbi_spi_transfer(struct spi_device *spi, u32 speed_hz, size_t chunk; int ret;
+ /* In __spi_validate, there's a validation that no partial transfers + * are accepted (xfer->len % w_size must be zero). + * Here we align max_chunk to multiple of 2 (16bits), + * to prevent transfers from being rejected. + */ + max_chunk = ALIGN_DOWN(max_chunk, 2); + spi_message_init_with_transfers(&m, &tr, 1);
while (len) {