5.4-stable review patch. If anyone has any objections, please let me know.
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From: Chandrakanth patil chandrakanth.patil@broadcom.com
commit 8e3ed9e786511ad800c33605ed904b9de49323cf upstream.
In BMC environments with concurrent access to multiple registers, certain registers occasionally yield a value of 0 even after 3 retries due to hardware errata. As a fix, we have extended the retry count from 3 to 30.
The same errata applies to the mpt3sas driver, and a similar patch has been accepted. Please find more details in the mpt3sas patch reference link.
Link: https://lore.kernel.org/r/20230829090020.5417-2-ranjan.kumar@broadcom.com Fixes: 272652fcbf1a ("scsi: megaraid_sas: add retry logic in megasas_readl") Cc: stable@vger.kernel.org Signed-off-by: Chandrakanth patil chandrakanth.patil@broadcom.com Signed-off-by: Sumit Saxena sumit.saxena@broadcom.com Link: https://lore.kernel.org/r/20231003110021.168862-2-chandrakanth.patil@broadco... Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/megaraid/megaraid_sas_base.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -252,13 +252,13 @@ u32 megasas_readl(struct megasas_instanc * Fusion registers could intermittently return all zeroes. * This behavior is transient in nature and subsequent reads will * return valid value. As a workaround in driver, retry readl for - * upto three times until a non-zero value is read. + * up to thirty times until a non-zero value is read. */ if (instance->adapter_type == AERO_SERIES) { do { ret_val = readl(addr); i++; - } while (ret_val == 0 && i < 3); + } while (ret_val == 0 && i < 30); return ret_val; } else { return readl(addr);