mmc: core: Enable the MMC host software queue for the SD card

Enable the MMC host software queue for the SD card if the host controller
supports the MMC host software queue.

On my Spreadtrum platform, I did not see any obvious performance changes
in 4K block size when changing to use hsq for the SD cards, I think the
reason is the SD card works at a low speed on my platform, and most of
time is spent in the hardware. But we can see some obvious improvements
when enabling the packed request based on hsq, that's why we still add hsq
support for the SD cards.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/0065b4631fef2d61c3b89d14a4ea4f2b7499ea56.1581478568.git.baolin.wang7@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index fe914ff..76c7add 100644 (file)
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1082,6 +1082,16 @@ retry:
                }
        }
 
+       if (host->cqe_ops && !host->cqe_enabled) {
+               err = host->cqe_ops->cqe_enable(host, card);
+               if (!err) {
+                       host->cqe_enabled = true;
+                       host->hsq_enabled = true;
+                       pr_info("%s: Host Software Queue enabled\n",
+                               mmc_hostname(host));
+               }
+       }
+
        if (host->caps2 & MMC_CAP2_AVOID_3_3V &&
            host->ios.signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
                pr_err("%s: Host failed to negotiate down from 3.3V\n",