From: Ben Walsh Date: Thu, 13 Jun 2024 21:25:42 +0000 (+0100) Subject: platform/chrome: cros_ec_lpc: Handle zero length read/write X-Git-Tag: v6.11-rc1~215^2~8 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b57cd5703a1618e87772094ac12c5ee7d6c35e2f;p=thirdparty%2Fkernel%2Flinux.git platform/chrome: cros_ec_lpc: Handle zero length read/write cros_ec_lpc_mec_read_bytes and cros_ec_lpc_mec_write_bytes call cros_ec_lpc_mec_in_range, which checks if addresses are in the MEC address range, and returns -EINVAL if the range given is not sensible. However cros_ec_lpc_mec_in_range was also returning -EINVAL for a zero length range. A zero length range should not be an error condition. cros_ec_lpc_mec_in_range now returns 1 in this case. cros_ec_lpc_io_bytes_mec checks for zero length, and returns immediately without beginning a transfer. Fixes: 68dbac0a58ef ("platform/chrome: cros_ec_lpc: MEC access can return error code") Fixes: 77a714325d09 ("platform/chrome: cros_ec_lpc: Fix error code in cros_ec_lpc_mec_read_bytes()") Signed-off-by: Ben Walsh Link: https://lore.kernel.org/r/20240613212542.403-1-ben@jubnut.com Signed-off-by: Tzung-Bi Shih --- diff --git a/drivers/platform/chrome/cros_ec_lpc_mec.c b/drivers/platform/chrome/cros_ec_lpc_mec.c index dfad934e65ca6..a56584171168c 100644 --- a/drivers/platform/chrome/cros_ec_lpc_mec.c +++ b/drivers/platform/chrome/cros_ec_lpc_mec.c @@ -93,9 +93,6 @@ static void cros_ec_lpc_mec_emi_write_address(u16 addr, */ int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length) { - if (length == 0) - return -EINVAL; - if (WARN_ON(mec_emi_base == 0 || mec_emi_end == 0)) return -EINVAL; @@ -132,6 +129,9 @@ int cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type, enum cros_ec_lpc_mec_emi_access_mode access, new_access; int ret; + if (length == 0) + return 0; + /* Return checksum of 0 if window is not initialized */ WARN_ON(mec_emi_base == 0 || mec_emi_end == 0); if (mec_emi_base == 0 || mec_emi_end == 0)