[PATCH v2] usb: renesas-xhci: Fix External ROM access timeouts

[PATCH v2] usb: renesas-xhci: Fix External ROM access timeouts

[Marek Vasut]

Increase the External ROM access timeouts to prevent failures during
programming of External SPI EEPROM chips. The current timeouts are
too short for some SPI EEPROMs used with uPD720201 controllers.

The current timeout for Chip Erase in renesas_rom_erase() is 100 ms ,
the current timeout for Sector Erase issued by the controller before
Page Program in renesas_fw_download_image() is also 100 ms. Neither
timeout is sufficient for e.g. the Macronix MX25L5121E or MX25V5126F.

MX25L5121E reference manual [1] page 35 section "ERASE AND PROGRAMMING
PERFORMANCE" and page 23 section "Table 8. AC CHARACTERISTICS (Temperature
= 0°C to 70°C for Commercial grade, VCC = 2.7V ~ 3.6V)" row "tCE" indicate
that the maximum time required for Chip Erase opcode to complete is 2 s,
and for Sector Erase it is 300 ms .

MX25V5126F reference manual [2] page 47 section "13. ERASE AND PROGRAMMING
PERFORMANCE (2.3V - 3.6V)" and page 42 section "Table 8. AC CHARACTERISTICS
(Temperature = -40°C to 85°C for Industrial grade, VCC = 2.3V - 3.6V)" row
"tCE" indicate that the maximum time required for Chip Erase opcode to
complete is 3.2 s, and for Sector Erase it is 400 ms .

Update the timeouts such, that Chip Erase timeout is set to 5 seconds,
and Sector Erase timeout is set to 500 ms. Such lengthy timeouts ought
to be sufficient for majority of SPI EEPROM chips.

[1] https://www.macronix.com/Lists/Datasheet/Attachments/8634/MX25L5121E,%203V,%20512Kb,%20v1.3.pdf
[2] https://www.macronix.com/Lists/Datasheet/Attachments/8750/MX25V5126F,%202.5V,%20512Kb,%20v1.1.pdf

Fixes: 2478be82de44 ("usb: renesas-xhci: Add ROM loader for uPD720201")
Cc: <stable@vger.kernel.org>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
---
V2: Move Cc: stable above ---
---
 drivers/usb/host/xhci-pci-renesas.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-pci-renesas.c b/drivers/usb/host/xhci-pci-renesas.c
index 620f8f0febb8..86df80399c9f 100644
--- a/drivers/usb/host/xhci-pci-renesas.c
+++ b/drivers/usb/host/xhci-pci-renesas.c
@@ -47,8 +47,9 @@
 #define RENESAS_ROM_ERASE_MAGIC				0x5A65726F
 #define RENESAS_ROM_WRITE_MAGIC				0x53524F4D
 
-#define RENESAS_RETRY	10000
-#define RENESAS_DELAY	10
+#define RENESAS_RETRY			50000	/* 50000 * RENESAS_DELAY ~= 500ms */
+#define RENESAS_CHIP_ERASE_RETRY	500000	/* 500000 * RENESAS_DELAY ~= 5s */
+#define RENESAS_DELAY			10
 
 #define RENESAS_FW_NAME	"renesas_usb_fw.mem"
 
@@ -407,7 +408,7 @@ static void renesas_rom_erase(struct pci_dev *pdev)
 	/* sleep a bit while ROM is erased */
 	msleep(20);
 
-	for (i = 0; i < RENESAS_RETRY; i++) {
+	for (i = 0; i < RENESAS_CHIP_ERASE_RETRY; i++) {
 		retval = pci_read_config_byte(pdev, RENESAS_ROM_STATUS,
 					      &status);
 		status &= RENESAS_ROM_STATUS_ERASE;
-- 
2.47.2